Resist underlayer film composition, patterning process, and method for forming resist underlayer film

ABSTRACT

Provided is a resist underlayer film composition which is excellent in resistance to a basic hydrogen peroxide aqueous solution, in gap-filling and planarization characteristics, and in dry etching characteristic, wherein the resist underlayer film composition is used for a multilayer resist method, comprising: (A1) a polymer (1A) comprising one, or two or more, of a repeating unit represented by following general formula (1); (A2) one, or two or more, of a polyphenol compound having a formula weight of 2,000 or less and not having a 3,4-dihydroxy phenyl group; and (B) an organic solvent.

TECHNICAL FIELD

The present invention relates to: a resist underlayer film compositionto be used for fine patterning by a multilayer resist method in asemiconductor device manufacturing process; a patterning process usingthe resist underlayer film composition, and a method for forming aresist underlayer film.

BACKGROUND ART

As LSI advances to a higher integration and a further facilitation inspeed, miniaturization of a pattern size is rapidly progressing. Inaccordance with this miniaturization movement, the lithographytechnology has achieved formation of a fine pattern by shifting thewavelength of a light source shorter and by proper selection of a resistcomposition responding to such shift in the light source. The mainfactor of this is a positive photoresist composition used in amonolayer. In this monolayer positive photoresist composition, askeleton having an etching resistance to dry etching by a gas plasma ofchlorine-based or fluorine-based is incorporated into a resist resin anda switching mechanism to dissolve an exposed part is constructed in aresist resin and thereby a pattern is formed by dissolving the exposedpart, and then, a substrate to be processed is dry-etched by using theremained resist pattern as an etching mask.

However, if miniaturization is pursued without changing a film thicknessof the photoresist film to be used, namely, if the pattern width thereofis made further narrower, resolution of the photoresist film decreases;in addition, if the photoresist film is pattern-developed by using adeveloper, a so-called aspect ratio thereof becomes so large that aproblem of the pattern fall occurs. In view of the above-mentioned, thethickness of the photoresist film has been made thinner in accordancewith this miniaturization movement.

On the other hand, for processing of a substrate to be processed, themethod wherein this substrate is dry-etched by using a photoresist filmhaving a formed pattern as an etching mask has been usually used.However, practically there is no dry etching method having a completeetching selectivity between the photoresist film and the substrate to beprocessed. Because of this, during processing of the substrate, theresist film is also damaged to cause collapse of the resist film so thatthere has been a problem that the resist pattern cannot be preciselytranscribed to the substrate to be processed. Because of this, theresist composition has been required to have a further higher dryetching resistance in accordance with the movement to a finer pattern.On the other hand, however, in order to increase a resolution, the resinused for the photoresist composition has been required to have a smallerlight absorbance at the wavelength of the exposure light. Therefore, asthe exposure light shifts to a shorter wavelength, i.e., shifting toi-beam, KrF, and ArF, the resin has also been shifting to a novolakresin, polyhydroxystyrene, and a resin having an aliphatic polycyclicskeleton. Realistically however, the etching rate under the dry etchingcondition during the substrate processing has been increased so thatrecent photoresist compositions having a high resolution tend to haverather a lower etching resistance.

In the situation as mentioned above, a substrate to be processed must beprocessed by dry etching by using a photoresist film having a thinnerthickness and a lower etching resistance than ever; and thus, securementof a material and a process in this patterning process has become anacute imperative.

One means to solve the problems mentioned above is a multilayer resistmethod. In this method, an intermediate film having the etchingselectivity different from that of a photoresist film (namely, a resistupper layer film) is put between the resist upper layer film and asubstrate to be processed; and after a pattern is formed on the resistupper layer film, this pattern is transcribed to the intermediate filmby dry etching using the pattern on the upper layer film as a dryetching mask, and then, the pattern is transcribed further to thesubstrate to be processed by dry etching using the intermediate film asa dry etching mask.

One of the multilayer resist methods is a three-layer resist method inwhich a general resist composition used in a monolayer resist method canbe used. In this three-layer resist method, for example, an organic filmformed of a novolak resin or the like is formed on the substrate to beprocessed as the resist underlayer film, on it a silicon-containing filmis formed as the resist intermediate film, and further on it a usualorganic photoresist film is formed as the resist upper layer film.Because the organic resist upper layer film can have a good selectivityrelative to the silicon-containing resist intermediate film in dryetching by a fluorine-based gas plasma, the resist upper layer filmpattern can be transcribed to the silicon-containing resist intermediatefilm by using dry etching by the fluorine-based gas plasma. According tothis method, even if a resist composition with which a pattern having asufficient film thickness to directly work on the substrate to beprocessed is difficult to be formed is used, or a resist compositionwhose dry etching resistance is insufficient to work on the substrate isused, the pattern can be transcribed to the silicon-containing film (theresist intermediate film), and then, by transcribing the pattern by thedry etching using an oxygen-based or a hydrogen-based gas plasma, thepattern of the organic film (resist underlayer film) formed of a novolakresin or the like having a sufficient dry etching resistance to thesubstrate processing can be obtained. Many of the resist underlayerfilms as mentioned above have already been in the public domain, suchas, for example, those described in Patent Document 1.

On the other hand, in recent years, production of the semiconductordevice having a novel structure such as a multi-gate structure is beingactively investigated; and with this movement, requirements for betterplanarization and gap-filling characteristics than before are increasingmore than before in the resist underlayer film. For example, when thereis a very fine pattern structure such as a hole, a trench, or a fin inthe underlayment substrate to be processed, the gap-fillingcharacteristic to fill up inside the pattern by the resist underlayerfilm without a void becomes necessary. Further, when there are steps onthe underlayment substrate to be processed, or when a dense pattern areaand a scarce pattern area co-exist on the same wafer, the film surfaceneeds to be planarized by the resist underlayer film. By planarizing theunderlayer film surface, variance of the film thickness of the resistintermediate film and the resist upper layer film to be formed thereuponcan be suppressed; and as a result, the decrease in a focus margin ofthe lithography as well as in a margin in the subsequent process step ofthe substrate to be processed can be suppressed. Alternatively, in orderto remove, by dry etching, the resist underlayer film used forgap-filling and planarization without leaving the residue thereof afterthe substrate processing, the resist underlayer film having the dryetching characteristics different from those of the above-mentioned, forexample, the resist underlayer film having the dry etching rate fasterthan that of the resist upper layer film, is sometimes required.Further, there is also a case that the substrate processing by wetetching using a chemical is required, wherein the resist underlayer filmacting as the processing mask is required to have a resistance to a wetetching solution.

Meanwhile, the background for requirement of the material matching tothe wet etching process in the multilayer resist method will beexplained in detail. In order to improve the semiconductor deviceperformance, technologies such as a three-dimensional transistor and athrough wiring are being used in the most advanced semiconductordevices. The patterning by using the multilayer resist method is carriedout also in the patterning process used for forming the inner structureof the semiconductor device as mentioned above. In the patterning likethis, there is a case that after the patterning a process in which thesilicon-containing resist intermediate film is removed without damagingthe said pattern is required. If this removal is insufficient, namely ifthe wafer is sent to subsequent manufacturing process steps while stillhaving residual substances to be cleaned, yield of the devicemanufacturing definitely decreases. With the miniaturization movement ofthe device as mentioned above, a higher cleanness is required in thecleaning step. In many cases, however, the main constituent element inthe conventional silicon-containing resist intermediate film and in thesemiconductor device substrate is silicon; and thus, even if the attemptis made to selectively remove the silicon-containing resist intermediatefilm by dry etching, the constituent ingredients are so similar witheach other that it has been difficult to suppress the damage to thesemiconductor device substrate. This problem cannot be solved even withthe wet etching using a usual fluorine-based removing agent. Therefore,a basic hydrogen peroxide aqueous solution, which is called as SC1(Standard Clean-1) that is generally used in the semiconductormanufacturing process, may be used as the removing solution (namely, wetetching solution) not damaging the semiconductor device substrate. Inthis case, conversely the resist underlayer film needs to have aresistance to the basic hydrogen peroxide aqueous solution.

As the resist underlayer film composition having a fast dry etching rateand being capable of planarizing the substrate having steps to be usedfor the semiconductor device manufacturing, for example, a compositioncontaining a polymer compound such as polyglycidyl methacrylate isproposed in Patent Document 2. Also as the resist underlayer filmcomposition having a fast dry etching rate to be used for thesemiconductor device manufacturing, in Patent Document 3, a compositioncontaining a copolymer that is produced by using monomers such as(meth)acrylic acid and glycidyl (meth)acrylate is proposed, and inPatent Document 4, a composition containing a crosslinking agent and acopolymer that is produced by using monomers such as hydroxypropylmethacrylate is proposed. However, in these heretofore knowncompositions there has been a problem that the resistance to the basichydrogen peroxide aqueous solution is insufficient.

As the resist underlayer film composition having the resistance to thebasic hydrogen peroxide aqueous solution, in Patent Document 5, acomposition containing, among others, a polymer having an epoxy groupand a carboxyl group protected by using a vinyl ether compound(acetal-protected ester) is proposed for a two-layer process not usingthe resist intermediate film. However, this composition is insufficientin the planarization characteristic, and thus, this is not suitable forpatterning of the substrate to be processed having irregular surface orsteps highly required especially in the most advanced process and inaddition, there has been problem that the resistance to the basichydrogen peroxide aqueous solution is still insufficient in view ofpractical use. As the resist underlayer film composition to be used forthe semiconductor device manufacturing having the resistance to thebasic hydrogen peroxide aqueous solution as well as a fast dry etchingrate and being capable of planarizing the substrate having steps, inPatent Document 6, a composition containing among others a polymerhaving an epoxy group and a carboxyl group protected by a t-butyl groupis proposed. However, there has been a problem in this composition thatthe resistance to the basic hydrogen peroxide aqueous solution is stillinsufficient in view of practical use.

Therefore, there have been requirements of the resist underlayer filmcomposition to be used for the semiconductor device manufacturing havinga high conformity to a wet etching process (namely, high resistance tothe basic hydrogen peroxide aqueous solution) and having at the sametime good gap-filling and planarization characteristics and dry etchingcharacteristic, as well as the patterning process using thiscomposition.

PRIOR ART DOCUMENTS Patent Documents

Patent Document 1: Japanese Patent Laid-Open Publication No. 2004-205685

Patent Document 2: Japanese Patent Laid-Open Publication No. S61-180241

Patent Document 3: Japanese Patent 3082473

Patent Document 4: Japanese Patent 4310721

Patent Document 5: International Patent Laid-Open Publication No.2015/030060

Patent Document 6: Japanese Patent Laid-Open Publication No. 2016-185999

SUMMARY OF INVENTION Technical Problem

The present invention was made in view of the situation mentioned above;and thus, it has an object to provide: a resist underlayer filmcomposition which is excellent in a resistance to a basic hydrogenperoxide aqueous solution, in gap-filling and planarizationcharacteristics, and in a dry etching characteristic; a patterningprocess using this composition; and a method for forming a resistunderlayer film.

Solution to Problem

To solve the problems as mentioned above, the present invention providesa resist underlayer film composition, wherein the resist underlayer filmcomposition is used for a multilayer resist method, comprising:

-   (A1) a polymer (1A) comprising one, or two or more, of a repeating    unit represented by following general formula (1);-   (A2) one, or two or more, of a polyphenol compound having a formula    weight of 2,000 or less and not having a 3,4-dihydroxy phenyl group;    and-   (B) an organic solvent,

wherein R⁰¹ represents a hydrogen atom or a methyl group; and R⁰²represents a group selected from following formulae (1-1) to (1-3),

wherein the dotted line represents a bonding hand.

The resist underlayer film composition as mentioned above can form aresist underlayer film which is excellent in the resistance to a basichydrogen peroxide aqueous solution, in the gap-filling and planarizationcharacteristics, and in the dry etching characteristic.

In this case, it is preferable that the (A2) component contain any oneof a compound represented by following general formula (2A) and acompound represented by following general formula (3A) or both,R

X′)_(m2)   (2A)wherein R represents a single bond or an organic group having 1 to 50carbon atoms; X′ represents a group represented by following generalformula (2B); and m2 represents an integer satisfying 1≤m2≤5,

wherein “n3” represents 0 or 1; “n4” represents 1 or 2; X⁴ represents agroup represented by following general formula (2C); and “n6” represents0, 1, or 2; however, “n4” represents 1 when “n3” is 0 and “n6” is 0,

wherein R¹¹ represents a hydrogen atom or a saturated or unsaturatedhydrocarbon group having 1 to 10 carbon atoms, wherein the hydrogen atomon the benzene ring may be optionally substituted by a methyl group or amethoxy group,

wherein R¹⁰¹, R¹⁰², R¹⁰³, and R¹⁰⁴ each represents independently ahydrogen atom or a hydroxyl group; “m100” represent 1, 2, or 3; R¹⁰⁰represents a hydrogen atom or a hydroxyl group when “m100” is 1, or asingle bond or a group represented by following general formula (3B)when “m100” is 2, or a group represented by following general formula(3C) when “m100” is 3, and further the hydrogen atom on the benzene ringmay be optionally substituted by a methyl group, a methoxy group, ahydroxymethyl group, or a methoxymethyl group; “m101” represents 0 or 1,“m102” represents 1 or 2, “m103” represents 0 or 1, “m104” represents 1or 2, and “m105” represents 0 or 1; when “m101” is 0, “n101” and “n102”represent an integer satisfying 0≤n101≤3, 0≤n102≤3, and 1≤n101+n102≤4;when “m101” is 1, “n101”, “n102”, “n103”, and “n104” represent aninteger satisfying 0≤n101≤2, 0≤n102≤2, 0≤n103≤2, 0≤n104≤2, and2≤n101+n102n+n103+n104≤8; however, when “m101” is 0 and “n102” is 0,“n101” represents 0 or 1 and “m100” represents 2 or 3; when “m103” is 0,“m102” represents 1; and when “m105” is 0, “m104” represents 1,

wherein * represents a bonding site; R¹⁰⁶ and R¹⁰⁷ represent a hydrogenatom or an organic group having 1 to 24 carbon atoms; and R¹⁰⁶ and R¹⁰⁷may be bonded to form a ring structure,

wherein * represents a bonding site; and R¹⁰⁸ represents a hydrogen atomor an organic group having 1 to 15 carbon atoms.

By blending the compounds as mentioned above, an organic film havingenhanced adhesion not only to a silicon substrate but also to, amongothers, a structural substrate formed of a silicone oxide or a siliconnitride as well as a hard mask formed of a titanium nitride or the likecan be formed. In addition, among others, film-formability by spincoating and a gap-filling characteristic in the substrate having stepscan also be improved.

In this case, it is preferable that the polymer (1A) further containone, or two or more, of a repeating unit represented by followinggeneral formula (2),

wherein R⁰¹ represents the same as before; A¹ represents a single bond,—CO₂—, or a divalent connecting group having 2 to 10 carbon atoms andincluding —CO₂—; and Ar¹ represents a substituted or unsubstituted arylgroup having 6 to 20 carbon atoms.

When the repeating unit as mentioned above is included, suitable opticalcharacteristics at the wavelength of 193 nm can be obtained, so that anexcellent resolution can be obtained because a reflected light can besuppressed upon exposure to a light, especially in a multilayer ArFlithography.

In this case, it is preferable that the polymer (1A) further containone, or two or more, of a repeating unit represented by followinggeneral formula (3),

wherein R⁰¹ represents the same as before; and R^(c) represents amonovalent group having 3 to 20 carbon atoms and having an alicyclicstructure.

When the repeating unit as mentioned above is properly included, withoutdeteriorating the optical characteristics the etching characteristicssuch as the etching rate and the pattern form after etching can becontrolled in accordance with customer's requirements.

In this case, it is preferable that a weight average molecular weight ofthe polymer (1A) be in a range of 1,000 to 20,000.

When the weight average molecular weight is 1,000 or more, there is norisk of deterioration in film-formability or fouling of the equipmentdue to increase in the sublimate during thermal curing. When the weightaverage molecular weight is 20,000 or less, there is no risk offormation of a coating defect or deterioration in the planarization andgap-filling characteristics due to decrease in the flowability.

In this case, it is preferable that the resist underlayer filmcomposition further contain one or more additives out of (C) an acidgenerator, (D) a surfactant, (E) a crosslinking agent, (F) aplasticizer, and (G) a pigment.

In the resist underlayer film composition of the present invention, theadditives as mentioned above may be added so as to facilitate thecrosslinking reaction by heat or the like, as well as to improvefilm-applicability by spin coating, curability, planarization andgap-filling characteristics, and resolution during patterning in themultilayer lithography.

In this case, it is preferable that the resist underlayer filmcomposition be the resist underlayer film composition which gives aresist underlayer film having a resistance to an ammonia-containinghydrogen peroxide aqueous solution.

When the resist underlayer film composition as mentioned above is used,the resist underlayer film which is excellent in the resistance to abasic hydrogen peroxide aqueous solution can be formed; and thus, thiscomposition can also be used in the wet etching process using the basichydrogen peroxide aqueous solution.

In this case, it is preferable that the resist underlayer film be theresist underlayer film which does not show any peel-off when a siliconsubstrate formed with the resist underlayer film is soaked into a 1.0%by mass hydrogen peroxide aqueous solution containing 0.5% by mass ofammonia at 70° C. for 5 minutes.

When the resist underlayer film composition as mentioned above is used,the resist underlayer film which is excellent in the resistance to thebasic hydrogen peroxide aqueous solution can be formed; and thus, thiscomposition can also be used sufficiently well in the wet etchingprocess using the basic hydrogen peroxide aqueous solution.

In addition, the present invention provides a patterning process,wherein the patterning process is to form a pattern on a substrate to beprocessed and comprises:

-   (I-1) forming a resist underlayer film on the substrate to be    processed by using the resist underlayer film composition,-   (I-2) forming a resist upper layer film on the resist underlayer    film by using a photoresist composition,-   (I-3) forming a pattern on the resist upper layer film by developing    the resist upper layer film by using a developer after the resist    upper layer film is pattern-exposed, and-   (I-4) transcribing the pattern to the resist underlayer film by dry    etching using as a mask the resist upper layer film formed with the    pattern.

In addition, the present invention provides a patterning process,wherein the patterning process is to form a pattern on a substrate to beprocessed and comprises:

-   (II-1) forming a resist underlayer film on the substrate to be    processed by using the resist underlayer film composition,-   (II-2) forming a resist intermediate film on the resist underlayer    film,-   (II-3) forming a resist upper layer film on the resist intermediate    film by using a photoresist composition,-   (II-4) forming a pattern on the resist upper layer film by    developing the resist upper layer film by using a developer after    the resist upper layer film is pattern-exposed,-   (II-5) transcribing the pattern to the resist intermediate film by    dry etching using as a mask the resist upper layer film formed with    the pattern, and-   (II-6) transcribing the pattern to the resist underlayer film by dry    etching using as a mask the resist intermediate film transcribed    with the pattern.

In addition, the present invention provides a patterning process,wherein the patterning process is to form a pattern on a substrate to beprocessed and comprises:

-   (III-1) forming a resist underlayer film on the substrate to be    processed by using the resist underlayer film composition,-   (III-2) forming an inorganic hard mask intermediate film selected    from a silicon oxide film, a silicon nitride film, and a silicon    oxide nitride film on the resist underlayer film,-   (III-3) forming an organic antireflective film on the inorganic hard    mask intermediate film,-   (III-4) forming a resist upper layer film on the organic    antireflective film by using a photoresist composition,-   (III-5) forming a pattern on the resist upper layer film by    developing the resist upper layer film by using a developer after    the resist upper layer film is pattern-exposed,-   (III-6) transcribing the pattern to the organic antireflective film    and the inorganic hard mask intermediate film by dry etching using    as a mask the resist upper layer film formed with the pattern, and-   (III-7) transcribing the pattern to the resist underlayer film by    dry etching using as a mask the inorganic hard mask intermediate    film transcribed with the pattern.

According to the patterning process of the present invention asmentioned above, fine patterning by the multilayer resist method(two-layer resist process, three-layer resist process, or the four-layerresist process) is possible; and in addition, by forming the resistunderlayer film, the gap in the steps on the substrate to be processedcan be filled, and the substrate to be processed can be planarized. Inaddition, the resist underlayer film formed by using the resistunderlayer film composition of the present invention is excellent in theresistance to the basic hydrogen peroxide aqueous solution so that thiscan also be used in the wet etching process using the basic hydrogenperoxide aqueous solution.

In addition, after the (II-6) step, the patterning process of thepresent invention may be further added with a step in which the resistintermediate film transcribed with the pattern is removed by wet etchingusing a basic hydrogen peroxide aqueous solution.

Because the resist underlayer film formed by using the resist underlayerfilm composition of the present invention is excellent in the resistanceto the basic hydrogen peroxide aqueous solution, the resist intermediatefilm can be removed by the wet etching using the basic hydrogen peroxideaqueous solution, as mentioned above.

In addition, after the (I-4) step, the (II-6) step, or the (III-7) step,the patterning process of the present invention may be further addedwith a step in which the pattern is transcribed to the substrate to beprocessed by wet etching using a basic hydrogen peroxide aqueoussolution and the resist underlayer film transcribed with the pattern asa mask.

Because the resist underlayer film formed by using the resist underlayerfilm composition of the present invention is excellent in the resistanceto the basic hydrogen peroxide aqueous solution, the pattern can betranscribed to the substrate to be processed by the wet etching usingthe basic hydrogen peroxide aqueous solution, as mentioned above.

In addition, after the (I-4) step, the (II-6) step, or the (III-7) step,the patterning process of the present invention may be further addedwith a step in which the substrate to be processed is pattern-processedby an ion implantation using as a mask the resist underlayer filmtranscribed with the pattern.

The patterning process as mentioned above is suitable especially forprocessing of the substrate having an irregular surface by the ionimplantation.

In this case, after the step of the patterning process of the substrateto be processed by the ion implantation, a step in which the resistintermediate film transcribed with the pattern is removed by wet etchingusing a basic hydrogen peroxide aqueous solution may be added.

Because the resist underlayer film formed by using the resist underlayerfilm composition of the present invention is excellent in the resistanceto the basic hydrogen peroxide aqueous solution, the resist intermediatefilm after the pattern processing by the ion implantation can also beremoved by the wet etching using the basic hydrogen peroxide aqueoussolution, as mentioned above.

In this case, it is preferable to use the resist underlayer filmcomposition having a dry etching rate faster than a dry etching rate ofthe resist upper layer film.

When the resist underlayer film composition as mentioned above is used,the resist underlayer film used as a mask can be removed by dry etchingwithout leaving a residual matter thereof, so that a semiconductordevice having less defects can be manufactured.

In this case it is preferable that the resist underlayer film be formedby applying the resist underlayer film composition onto the substrate tobe processed followed by heat-treatment thereof in a temperature 100° C.or more and 300° C. or less, both ends inclusive, for a period of in arange of 10 to 600 seconds.

Under the conditions as mentioned above, the resist underlayer filmhaving flat surface can be formed without forming voids even on thesubstrate having irregular surface; and in addition, the crosslinkingreaction can be facilitated so that mixing with upper layer films can beprevented. In addition, when the heat-treatment temperature and theheat-treatment period are properly controlled within the above-mentionedranges, the gap-filling and planarization characteristics as well as thecuring characteristic, these characteristics matching with individualuse, can be obtained.

In this case, it is preferable to use, as the substrate to be processed,a substrate having a structural body with a height of 30 nm or more, orhaving a step.

Because the resist underlayer film formed by using the resist underlayerfilm composition of the present invention is excellent in thegap-filling and planarization characteristics, the resist underlayerfilm having flat surface can also be formed without forming voids evenon the substrate having the structural body with the height of 30 nm ormore, or having the step.

In addition, the present invention provides a method for forming aresist underlayer film wherein the resist underlayer film compositionmentioned above is applied onto a substrate to be processed, and then,the resist underlayer film composition is subjected to heat-treatment ina temperature range of 100° C. or more and 300° C. or less, both endsinclusive, for a period of in a range of 10 to 600 seconds to form acured film.

When the method for forming the resist underlayer film is the one asmentioned above, the resist underlayer film which is excellent in theresistance to the basic hydrogen peroxide aqueous solution, in thegap-filling and planarization characteristics, and in the dry etchingcharacteristic can be formed. In addition, when the baking temperatureand the baking period are properly controlled within the above-mentionedranges, the gap-filling and planarization characteristics as well as thecuring characteristic, these characteristics matching with individualuse, can be obtained.

In this case, it is preferable to use a substrate having a structuralbody with a height of 30 nm or more, or having a step as the substrateto be processed.

The method of the present invention for forming the resist underlayerfilm is useful especially for forming a planarized organic film withoutvoids on the substrate having the structural body with the height of 30nm or more, or having the step.

Advantageous Effects of Invention

As explained above, according to the resist underlayer film compositionof the present invention, the resist underlayer film which is excellentin the resistance to the basic hydrogen peroxide aqueous solution, inthe gap-filling and planarization characteristics, and in the dryetching characteristic can be formed.

In addition, according to the patterning process of the presentinvention, a fine pattern can be formed by the multilayer resist method(two-layer resist process, three-layer resist process, or the four-layerresist process); and in addition, by forming the resist underlayer film,the steps on the substrate to be processed can be filled, and thesubstrate to be processed can be planarized. Therefore, the patterningprocess of the present invention can be favorably used in the wetetching process, in the planarization process by formation of theunderlayer film, and in the removal process of the underlayer film bydry etching; and thus, this method is extremely useful as the patterningprocess used in the multilayer resist process used in the finepatterning for the semiconductor device manufacturing.

In addition, according to the method of the present invention forforming a resist underlayer film, the resist underlayer film which isexcellent in the resistance to the basic hydrogen peroxide aqueoussolution, in the gap-filling and planarization characteristics, and inthe dry etching characteristic can be formed.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an explanatory drawing of one example of the patterningprocess by the three-layer resist process according to the presentinvention;

FIG. 2 is an explanatory drawing of the evaluation method of thegap-filling characteristic in Examples and Comparative Examples; and

FIG. 3 is an explanatory drawing of the evaluation method of theplanarization characteristic in Examples and Comparative Examples.

DESCRIPTION OF EMBODIMENTS

As mentioned above, those having been wanted are: the resist underlayerfilm composition which is excellent in the resistance to the basichydrogen peroxide aqueous solution, in the gap-filling and planarizationcharacteristics, and in the dry etching characteristic; the patterningprocess using this composition; and the method for forming a resistunderlayer film.

In order to realize the wet etching processing in the multilayerlithography using a resist underlayer film, more desirably, in order tofurther realize gap-filling and planarization by formation of theunderlayer film as well as removal of the underlayer film by dryetching, inventors of the present invention have explored various resistunderlayer film compositions and patterning processes. As a result, itwas found that the resist underlayer film composition mainly comprisinga polymer having a certain structure and a polyphenol compound, as wellas the patterning process is very effective for these purposes; and onthe basis of these findings, the present invention could be completed.

Namely, the resist underlayer film composition of the present inventionis a resist underlayer film composition to be used for a multilayerresist method, the composition comprising: (A1) a polymer (1A)comprising one, or two or more, of a repeating unit represented byfollowing general formula (1); (A2) one, or two or more, of a polyphenolcompound having a formula weight of 2,000 or less and not having a3,4-dihydroxy phenyl group; and (B) an organic solvent,

wherein R⁰¹ represents a hydrogen atom or a methyl group; and R⁰²represents a group selected from following formulae (1-1) to (1-3),

wherein the dotted line represents a bonding hand.

Hereunder, the present invention will be explained in more detail;however, the present invention is not limited to these descriptions.

<Resist Underlayer Film Composition>

The resist underlayer film composition of the present invention is aresist underlayer film composition to be used for a multilayer resistmethod, the composition comprising: (A1) a polymer (1A) comprising one,or two or more, of a repeating unit represented by following generalformula (1); (A2) one, or two or more, of a polyphenol compound having aformula weight of 2,000 or less and not having a 3,4-dihydroxy phenylgroup; and (B) an organic solvent, whereby the resist underlayer filmcomposition of the present invention contains the (Al) component and the(A2) component as the base resins,

wherein R⁰¹ represents a hydrogen atom or a methyl group; and R⁰²represents a group selected from following formulae (1-1) to (1-3),

wherein the dotted line represents a bonding hand. Hereunder, eachcomponent will be explained in more detail.[(A1) Component]

The (A1) component is the polymer (1A) comprising one, or two or more,of the repeating unit represented by the general formula (1). Therepeating unit represented by the general formula (1) provides thepolymer (1A) with a sufficient thermal curability and with a preventiveeffect of intermixing with the upper layer films. In addition, it ispresumed that this can contribute to the resistance to the basichydrogen peroxide aqueous solution to a certain degree.

In the general formula (1), R⁰¹ represents a hydrogen atom or a methylgroup. When R⁰¹ is a hydrogen atom, the polymer (1A) is excellent in itsflowability, thereby sometimes contributing to enhancement of theplanarization and gap-filling characteristics as well as enhancement ofthe etching rate because of small carbon content. On the other hand,when R⁰¹ is a methyl group, there is a case that the resist underlayerfilm composition of the present invention has excellent film formabilityand applicability. R⁰² represents the group selected from the aboveformulae (1-1) to (1-3).

The polymer (1A) may contain only one, or two or more, of the repeatingunit represented by the general formula (1). Specifically, the repeatingunits represented by the general formula (1) are as follows,

It is more preferable that the polymer (1A) contain one, or two or more,of the repeating unit represented by the following general formula (2),

wherein R⁰¹ represents the same as before; A¹ represents a single bond,—CO₂—, or a divalent connecting group having 2 to 10 carbon atoms andincluding —CO₂—; and Ar¹ represents a substituted or an unsubstitutedaryl group having 6 to 20 carbon atoms.

The repeating unit represented by the general formula (2) can providethe base resin with suitable optical characteristics at the wavelengthof 193 nm; and thus, when the repeating unit like this is includedtherein, the reflected light can be suppressed especially during thetime of exposure to a light in the multilayer ArF lithography, andthereby excellent resolution can be obtained. Meanwhile, in order tosuppress the reflected light, it is preferable that the refractive indexn be in the range of 1.5 to 1.9 and the extinction coefficient “k” be inthe range of 0.1 to 0.5 as the optical constants of the resistunderlayer film composition.

In the general formula (2), R⁰¹ represents a hydrogen atom or a methylgroup. A¹ represents a single bond, —CO₂—, or a divalent connectinggroup having 2 to 10 carbon atoms and including —CO₂—. Specific exampleof A¹ includes a single bond, —CO₂—, —CO₂CH₂—, —CO₂CH₂CH₂—,—CO₂CH₂CH₂CH₂—, —CO₂CH (CH₃)—, —CO₂CH₂CH₂CH₂CH₂—,—CO₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂—, —CO₂CH₂CH₂O—, —CO₂CH₂CH₂OCH₂CH₂O—, and—CO₂CH₂CH₂OCH₂CH₂OCH₂CH₂O—, but not limited to them. Ar¹ represents asubstituted or unsubstituted aryl group having 6 to 20 carbon atoms.More specific example of the Ar¹ includes a phenyl group, a tollylgroup, a xylyl group, a methoxyphenyl group, a tert-butoxyphenyl group,a hydroxyphenyl group, an acetylphenyl group, a naphthyl group, amethylnaphthyl group, an anthracenyl group, a phenanthrenyl group, and apyrenyl group, wherein especially preferable groups are a phenyl groupand a tert-butoxyphenyl group, though not limited to them.

It is more preferable that the polymer (1A) include one, or two or more,of the repeating unit represented by the following general formula (3),

wherein R⁰¹ represents the same as before; and R^(c) represents amonovalent group having 3 to 20 carbon atoms and having an alicyclicstructure.

When the repeating unit represented by the general formula (3) isappropriately introduced, without deteriorating optical characteristicsof the base resin the etching characteristics such as the etching rateand the pattern form after etching can be controlled in accordance withthe customer's requirement.

In the general formula (3), R⁰¹ represents a hydrogen atom or a methylgroup. R^(c) represents a monovalent group having 3 to 20 carbon atomsand having an alicyclic structure. More specific example of R^(c)includes a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, acyclohexyl group, a cycloheptyl group, a dicycloheptyl group, adicyclooctyl group, a dicyclononyl group, a dicyclodecanyl group, atricyclodecanyl group, an adamantyl group, a tetracyclododecanyl group,a cyclohexylmethyl group, a dicycloheptylmethyl group, an isobornylgroup, a menthyl group, a hydroxycyclohexyl group, ahydroxydicycloheptyl group, a hydroxyadamantyl group, a1-methylcyclopropyl group, a 1-methylcyclopentyl group, a1-ethylcyclopentyl group, a 1-methylcyclohexyl group, a1-ethylcyclohexyl group, a 1-cyclopentylcyclopentyl group, a1-cyclohexylcyclopentyl group, a 1-methylcyclohexyl group, a1-ethylcyclohexyl group, a 1-cyclopentylcyclohexyl group, a1-cyclohexylcyclohexyl group, a 2-methyl-2-norbonyl group, a2-ethyl-2-norbonyl group, a 8-methyl-8-tricyclo[5.2.1.0^(2,6)]decylgroup, a 8-ethyl-8-tricyclo[5.2.1.0^(2,6)]decyl group, a3-methyl-3-tetracyclo[4.4.0.1^(2,5),1^(7,10)]dodecyl group, a3-ethyl-3-tetracyclo[4.4.0.1^(2,5),1^(7,10)]dodecyl group, a2-methyl-2-adamantyl group, a 2-ethyl-2-adamantyl group, a1-adamantyl-1-methylethyl group, a 1-methyl-3-oxo-1-cyclohexyl group, a1-methyl-1-(tetrahydrofuran-2-yl)ethyl group, a5-hydroxy-2-methyl-2-adamantyl group, a 5-hydroxy-2-ethyl-2-adamantylgroup, a butyrolactonyl group, a valerolactonyl group, a1,3-cyclohexanecarbolactonyl group, a4-oxa-5-oxotricyclo[5.2.1.0^(2,6)]decyl group, a2,6-norbornanecarbolactone-3-ylmethyl group, a2,6-norbornanecarbolactone-5-yl group, a3-methoxycarbonyl-2,6-norbornanecarbolactone-5-yl group, and a7-oxa-2,6-norbornanecarbolactone-5-yl group. When an optimum structureis selected as R^(c) in accordance with the use, properties of theentire polymer such as the carbon density and polarity can be optimallycontrolled so that the characteristics of the underlayer film which usesthis polymer can be controlled as well.

In the present invention, the mole fraction of the repeating unitrepresented by the general formula (1) in the polymer (1A) is preferably20% or more and 90% or less, both ends inclusive, while more preferably25% or more and 70% or less, both ends inclusive. When the mole fractionthereof is 20% or more, sufficient curability can be obtained. When themole fraction thereof is 70% or less, sufficient planarization andetching characteristics can be obtained.

Meanwhile, when the sum of mole fractions of the repeating unitsrepresented by the general formula (1) does not reach 100%, the polymer(1A) includes other repeating units. In this case, illustrative exampleof the other repeating unit includes the repeating unit derived any oneof those represented by the general formula (2) or the general formula(3); α,β-unsaturated carboxylate esters such as other acrylate esters,other methacrylate esters, crotonate esters, maleate esters, anditaconate esters; α,β-unsaturated carboxylic acids such as methacrylicacid, acrylic acid, maleic acid, and itaconic acid; acrylonitrile;methacrylonitrile; α,β-unsaturated lactones such as5,5-dimethyl-3-methylene-2-oxotetrahydrofuran; cyclic olefins such asnorbornene derivatives and tetracyclo[4.4.0.1^(2,5) .1^(7,10)]dodecenederivatives; α,β-unsaturated carboxylic acid anhydrides such as maleicanhydride and itaconic anhydride; allyl ethers; vinyl ethers; vinylesters; and vinyl silanes.

It is preferable that the polymer (1A) have the weight average molecularweight of in the range of 1,000 to 20,000. The weight average molecularweight is on the basis of the value measured by a gel permeationchromatography (solvent of tetrahydrofuran and the polystyrenestandard). The weight average molecular weight of the polymer (1A) ispreferably in the range of 1,000 to 20,000, more preferably in the rangeof 1,500 to 15,000, while still more preferably in the range of 2,000 to10,000. When the weight average molecular weight is 1,000 or more, thereis no risk of poor film-formability or fouling of the equipment due toincrease in the sublimate during thermal curing. When the weight averagemolecular weight is 20,000 or less, there is no risk of formation of acoating defect or deterioration in the planarization and gap-fillingcharacteristics due to decrease in the flowability.

In the resist underlayer film composition of the present invention, theglass transition temperature of the polymer (1A) is preferably 50° C. orless. When the resist underlayer film composition containing the polymer(1A) as mentioned above is used, the planarization and gap-fillingcharacteristics due to formation of the resist underlayer film areespecially good, so that this is especially desirable for processing ofthe substrate having an irregular surface.

In the resist underlayer film composition of the present invention, theGPC dispersibility of the polymer (1A) is preferably 2.0 or less. Whenthe resist underlayer film composition containing the polymer (1A) likethis is used, generation of the sublimate during formation of the resistunderlayer film is small, so that fouling of the equipment can besuppressed; and thus, this is excellent in the practical use.

It is preferable that the polymer (1A) in the resist underlayer filmcomposition of the present invention contain at least one repeating unitrepresented by the general formula (1), wherein it is preferable thatthe mole fraction of the repeating unit thereof represented by thegeneral formula (1) be 20% or more and 90% or less, both ends inclusive,the weight average molecular weight thereof be in the range of 1,000 to20,000, the glass transition temperature thereof be 50° C. or less, andthe GPC dispersibility thereof be 2.0 or less.

Specific example of the polymer (1A) in the resist underlayer filmcomposition of the present invention includes the polymers describedbelow, but the polymer (1A) is not limited to them. In the formulae, Merepresents a methyl group; Bu represents a butyl group; Ac represents anacetyl group; Ph represents a phenyl group; and tBu represents a t-butylgroup; and the same are applied hereinafter.

In the present invention, the polymer (1A) may be used singly or as amixture of two or more of them. Alternatively, the polymer (1A) may beused as a mixture with a resin not containing the repeating unitsrepresented by the general formulae (1), (2), and (3). In this case, theresin allowed to be mixed therewith is not particularly restricted, sothat heretofore known resins may be used. However, specifically anacrylic resin, a styrenic resin, a phenol resin, a polyether resin, andan epoxy resin are preferable.

For synthesis of the polymer (1A), one method thereof is the way inwhich monomers having polymerizable unsaturated bonds corresponding tothe respective repeating units are mixed, and then a thermalpolymerization of the mixture is carried out in a solvent by addition ofa radical polymerization initiator so as to obtain the polymer. Thepolymerization condition can be arbitrarily chosen in accordance withthe monomers to be used, a target molecular weight, and so forth, sothat the condition is not particularly restricted, while specificexample of the solvent to be used in the polymerization includestoluene, benzene, tetrahydrofuran, diethyl ether, dioxane, 2-butanone,methyl isobutyl ketone, propylene glycol monomethyl ether acetate,cyclohexanone, γ-butyrolactone, ethyl acetate, and butyl acetate.Illustrative example of the polymerization initiator includes2,2′-azobisisobutyronitrile (AIBN),2,2′-azobis(2,4-dimethylvaleronitrile), dimethyl2,2-azobis(2-methylpropionate), benzoyl peroxide, and lauroyl peroxide.As a chain transfer agent, a thiol such as octanethiol or2-mercaptoethanol may be added at the time of polymerization. Thepolymerization reaction may be carried out by heating in the temperaturerange of preferably 40° C. to a boiling point of the reaction solvent.The reaction time is in the range of 0.5 to 100 hours, while preferablyin the range of 1 to 48 hours.

For example, when the polymerization as mentioned above is carried outby using as the monomer a compound having the polymerizable double bondrepresented by the following general formula (1a), the polymer (polymercompound) containing the repeating unit represented by the generalformula (1) can be synthesized,

wherein R⁰¹ and R⁰² represent the same as before.

The polymerization may be carried out in such a way that heating iscarried out after all the raw materials are mixed, or alternatively,after part of the raw materials is heated in advance, and then, the restof the raw materials is added separately or as a mixture, all at once orgradually. For example, the polymerization method in which only thepolymerization solvent is heated, and then into it, a monomer solutionand an initiator solution are separately and gradually added may beemployed. This method not only can give a relatively homogeneous polymerbut also can avoid an abnormal reaction such as a runway reaction; andthus, this method is especially preferable.

The polymerization solution thus obtained may be blended into the resistunderlayer film composition as it is, or alternatively, the polymer maybe purified by using a usual method such as crystallization, phaseseparation, filtration, or concentration so as to remove residualmonomers, residual solvent, reaction byproducts, and other impurities.When the polymer (1A) is purified, the preferable method for it is acrystallization method in which a poor solvent such as water, awater-containing alcohol, or a saturated hydrocarbon is added into thepolymerization solution so as to collect the formed precipitate byfiltration, or a phase separation method in which a poor solvent phaseis removed by separation; but between them, the phase separation methodis especially preferable. When the polymer is purified by the phaseseparation method, low molecular weight components in the polymerizationsolution can be efficiently removed, so that the generation of sublimateduring the time of forming the resist underlayer film from the resistunderlayer film composition that contains the polymer can be suppressed;and thus, this is preferable in view of prevention of fouling of thefilm-forming equipment.

[(A2) Component]

The (A2) component in the resist underlayer film composition of thepresent invention is a polyphenol compound having a formula weight of2,000 or less and not having a 3,4-dihydroxy phenyl group. Thepolyphenol compound of the (A2) component is a compound having pluralphenolic hydroxyl groups in the molecule thereof, and is notparticularly restricted so far as this does not have the 3,4-dihydroxyphenyl group in the molecule thereof and is soluble in an organicsolvent (B) to be mentioned later, wherein they can be used singly or asa mixture of two or more of them. Number of the phenolic hydroxyl groupin the polyphenol compound of the (A2) component is more preferably inthe range of 3 to 20, while still more preferably in the range of 4 to10. When the number of the phenolic hydroxyl group is 3 or more, asufficient blending effect can be obtained; and when the number of thephenolic hydroxyl group is 20 or less, the resistance to theammonia-containing hydrogen peroxide aqueous solution can be obtainedsufficiently well. The formula weight (molecular weight) of thepolyphenol compound of the (A2) component is 2,000 or less, preferablyin the range of 300 to 2,000, while especially preferably in the rangeof 500 to 1,500. When the molecular weight is more than 2,000, there isa case that the planarization and gap-filling characteristics aredeteriorated. On the other hand, when the molecular weight is 300 ormore, there is no risk of poor film-formability or fouling of theequipment due to increase in the sublimate during thermal curing.

It is preferable that the polyphenol compound of the (A2) componentcontain any one of a compound represented by the following generalformula (2A) and a compound represented by the following general formula(3A) or both. However, both the compound represented by the generalformula (2A) and the compound represented by the general formula (3A)have plural phenolic hydroxyl groups in the respective moleculesthereof,R

X′)_(m2)   (2A)wherein R represents a single bond or an organic group having 1 to 50carbon atoms; X′ represents a group represented by the following generalformula (2B); and m2 represents an integer satisfying 1≤m2≤5,

wherein “n3” represents 0 or 1; n4 represents 1 or 2; X⁴ represents agroup represented by following general formula (2C); and n6 represents0, 1, or 2; however, “n4” represents 1 when “n3” is 0 and “n6” is 0,

wherein R¹¹ represents a hydrogen atom or a saturated or unsaturatedhydrocarbon group having 1 to 10 carbon atoms, and the hydrogen atom onthe benzene ring may be optionally substituted by a methyl group or amethoxy group,

wherein R¹⁰¹, R¹⁰², R¹⁰³, and R¹⁰⁴ each represents independently ahydrogen atom or a hydroxyl group; m100 represent 1, 2, or 3; R¹⁰⁰represents a hydrogen atom or a hydroxyl group when “m100” is 1, or asingle bond or a group represented by following general formula (3B)when “m100” is 2, or a group represented by following general formula(3C) when “m100” is 3, and the hydrogen atom on the benzene ring may beoptionally substituted by a methyl group, a methoxy group, ahydroxymethyl group, or a methoxymethyl group; “m101” represents 0 or 1,“m102” represents 1 or 2, “m103” represents 0 or 1, “m104” represents 1or 2, and m105 represents 0 or 1; when “m101” is 0, “n101” and “n102”represent an integer satisfying 0≤n101≤3, 0≤n102≤3, and 1≤n101+n102≤4;when “m101” is 1, “n101”, “n102”, “n103”, and “n104” represent aninteger satisfying 0≤n101≤2, 0≤n102≤2, 0≤n103≤2, 0≤n104≤2, and2≤n101+n102+n103+n104≤8; however, when “m101” is 0 and “n102” is 0,“n101” represents 0 or 1 and “m100” represents 2 or 3; when “m103” is 0,“m102” represents 1; and when “m105” is 0, “m104” represents 1,

wherein * represents a bonding site; R¹⁰⁶ and R¹⁰⁷ represent a hydrogenatom or an organic group having 1 to 24 carbon atoms; and R¹⁰⁶ and R¹⁰⁷may be bonded to form a ring structure,

wherein * represents a bonding site; and R¹⁰⁸ represents a hydrogen atomor an organic group having 1 to 15 carbon atoms.

Specific example of the compounds represented by the general formula(2A) and the general formula (3A) includes the compounds describedbelow. Meanwhile, an arbitrary hydrogen atom on the aromatic ring of thefollowing compounds may be optionally substituted by a methyl group, amethoxy group, a hydroxymethyl group, or a methoxymethyl group,

When any one of the compound represented by the general formula (2A) andthe compound represented by the general formula (3A) or both is/areblended, an organic film having improved adhesion to, among others, notonly a silicon substrate but also structural substrate formed withsilicon oxide or silicon nitride, as well as a hard mask formed withtitanium nitride or the like can be formed. In addition,film-formability by spin coating, gap-filling characteristics on thesubstrate having steps, and so forth can also be improved.

In addition, the resist underlayer film composition of the presentinvention may be blended further with other compound or polymer. Thecompound for blending or the polymer for blending has a role to improvethe film-formability by spin coating or the gap-filling characteristicon the substrate having steps when the resist underlayer filmcomposition is mixed with the (A1) and (A2) components. With regard tothe compound for blending or the polymer for blending, a compound havinga phenolic hydroxyl group is preferable.

With regard to the material as mentioned above, following materials maybe mentioned; namely, novolak resins of phenol, o-cresol, m-cresol,p-cresol, 2,3-dimethylphenol, 2,5-dimethylphenol, 3,4-dimethylphenol,3,5-dimethylphenol, 2,4-dimethylphenol, 2,6-dimethylphenol,2,3,5-trimethylphenol, 3,4,5-trimethylphenol, 2-tert-butylphenol,3-tert-butylphenol, 4-tert-butylphenol, 2-phenylphenol, 3-phenylphenol,4-phenylphenol, 3,5-diphenylphenol, 2-naphthylphenol, 3-naphthylphenol,4-naphthylphenol, 4-tolytylphenol, resorcino1,2-methylresorcinol,4-methylresorcinol, 5-methylresorcinol, catechol, 4-tert-butylcatechol,2-methoxyphenol, 3-methoxyphenol, 2-propylphenol, 3-propylphenol,4-propylphenol, 2-isopropylphenol, 3-isopropylphenol, 4-isopropylphenol,2-methoxy-5-methylphenol, 2-tert-butyl-5-methylphenol, pyrogallol,thymol, isothymol, 4,4′-(9H-fluorene-9-ylidene)bisphenol,2,2′dimethyl-4,4′-(9H-fluorene-9-ylidene)bisphenol,2,2′diallyl-4,4′-(9H-fluorene-9-ylidene)bisphenol,2,2′difluoro-4,4′-(9H-fluorene-9-ylidene)bisphenol,2,2′diphenyl-4,4′-(9H-fluorene-9-ylidene)bisphenol,2,2′dimethoxy-4,4′-(9H-fluorene-9-ylidene)bisphenol,2,3,2′,3′-tetrahydro-(1,1′)-spirobiindene-6,6′-diol,3,3,3′,3′-tetramethyl-2,3,2′,3′-tetrahydro-(1,1′)-spirobiindene-6,6′-diol,3,3,3′,3′,4,4′-hexamethyl-2,3,2′,3′-tetrahydro-(1,1′)-spirobiindene-6,6′-diol,2,3,2′,3′-tetrahydro-(1,1′)-spirobiindene-5,5′-diol,5,5′-dimethyl-3,3,3′,3′-tetramethyl-2,3,2′,3′-tetrahydro-(1,1′)-spirobiindene-6,6′-diol,1-naphthol, 2-naphthol, 2-methyl-1-naphthol, 4-methoxy-1-naphthol,7-methoxy-2-naphthol, dihydroxy naphthalenes such as1,5-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, and2,6-dihydroxynaphthalene, methyl 3-hydroxynaphthalene-2-carboxylate,indene, hydroxyindene, benzofuran, hydroxyanthracene, acenaphthylene,biphenyl, bisphenol, trisphenol, dicyclopentadiene, tetrahydroindene,4-vinylcyclohexene, norbornadiene, 5-vinylnoroborna-2-ene, α-pinene,β-pinene, and limonene; polyhydroxystyrene, polystyrene, polyvinylnaphthalene, polyvinyl anthracene, polyvinyl carbazole, polyindene,polyacenaphthylene, polynorbornene, polycyclodecene,polytetracyclododecene, polynortricyclene, poly(meth)acrylate, and theircopolymers. Further, naphthol-dicyclopentadiene copolymer described inJapanese Patent Laid-Open Publication No. 2004-205685, a fluorenebisphenol novolak resin described in Japanese Patent Laid-OpenPublication No. 2005-128509, an acenaphthylene copolymer described inJapanese Patent Laid-Open Publication No. 2005-250434, a fullerenecontaining a phenol group described in Japanese Patent Laid-OpenPublication No. 2006-227391, a bisphenol compound and a novolak resinthereof described in Japanese Patent Laid-Open Publication No.2006-293298, a novolak resin of an adamantane phenol compound describedin Japanese Patent Laid-Open Publication No. 2006-285095, a bisnaphtholcompound and a novolak resin thereof described in Japanese PatentLaid-Open Publication No. 2010-122656, a fullerene resin compounddescribed in Japanese Patent Laid-Open Publication No. 2008-158002, orthe like may also be blended. Amount of the compound for blending or thepolymer for blending is preferably in the range of 0.001 to 100 parts bymass, while more preferably in the range of 0.01 to 50 parts by mass,relative to 100 parts by mass as the total mass of the (A1) componentand the (A2) component.

[(B) Component]

The (B) component in the resist underlayer film composition of thepresent invention is an organic solvent. The organic solvent (B) usablein the resist underlayer film composition of the present invention isnot particularly restricted so far as it can dissolve the polymer of the(A1) component and the polyphenol compound of the (A2) component; and inaddition, it is preferable that the solvent can also dissolve (C) anacid generator, (D) a surfactant, (E) a crosslinking agent, (F) aplasticizer, and (G) a pigment (these additives will be discussedlater). Specifically, the solvents described in the paragraphs [0091] to[0092] of Japanese Patent Laid-Open Publication No.2007-199653 may beadded. Among them, preferable solvents are as follows: propylene glycolmonomethyl ether acetate, propylene glycol monomethyl ether, propyleneglycol monoethyl ether, propylene glycol monopropyl ether, 2-heptanone,cyclopentanone, cyclohexanone, 1-octanol, 2-ethylhexanol, 1-nonanol,1-decanol, 1-undecanol, ethylene glycol, 1,2-propylene glycol,1,3-butylene glycol, 2,4-pentanediol, 2-methyl-2,4-pentanediol,2,5-hexanediol, 2,4-heptanediol, 2-ethyl-1,3-hexanediol, diethyleneglycol, dipropylene glycol, triethylene glycol, tripropylene glycol,glycerin, n-nonyl acetate, monohexyl ether, ethylene glycolmono-2-ethylhexyl ether, ethylene glycol monophenyl ether, ethyleneglycol monobenzyl ether, diethylene glycol monoethyl ether, diethyleneglycol monoisopropyl ether, diethylene glycol mono-n-butyl ether,diethylene glycol monoisobutyl ether, diethylene glycol monohexyl ether,diethylene glycol monophenyl ether, diethylene glycol monobenzyl ether,diethylene glycol diethyl ether, diethylene glycol dibutyl ether,diethylene glycol butyl methyl ether, triethylene glycol dimethyl ether,triethylene glycol monomethyl ether, triethylene glycol-n-butyl ether,triethylene glycol butyl methyl ether, tetraethylene glycol dimethylether, dipropylene glycol monomethyl ether, dipropylene glycolmono-n-propyl ether, dipropylene glycol mono-n-butyl ether, tripropyleneglycol dimethyl ether, tripropylene glycol monomethyl ether,tripropylene glycol mono-n-propyl ether, tripropylene glycolmono-n-butyl ether, ethylene glycol monoethyl ether acetate, ethyleneglycol monobutyl ether acetate, diethylene glycol monomethyl etheracetate, diethylene glycol monoethyl ether acetate, diethylene glycolmonobutyl ether acetate, triacetin, propylene glycol diacetate,dipropylene glycol methyl-n-propyl ether, dipropylene glycol methylether acetate, 1,4-butanediol diacetate, 1,3-butylene glycol diacetate,1,6-hexanediol diacetate, γ-butyrolactone, as well as mixtures of two ormore of the above-mentioned solvents.

[(C) Component]

The resist underlayer film composition of the present invention may beblended with (C) an acid generator in order to further facilitate acrosslinking reaction by heat or the like. There are acid generatorsgenerating an acid by thermal decomposition or by photo irradiation,wherein any of them may be blended.

Illustrative example of the acid generator (C) which can be used in theresist underlayer film composition of the present invention includesfollowing compounds:

-   i. onium salts represented by the following general formulae    (Pla-1), (Pla-2), (Pla-3), or (P1b),-   ii diazomethane derivatives represented by the following general    formula (P2),-   iii glyoxime derivatives represented by the following general    formula (P3),-   iv bissulfone derivatives represented by the following general    formula (P4),-   v sulfonate esters of N-hydroxyimide compounds represented by the    following general formula (P5),-   vi β-ketosulfonic acid derivatives,-   vii disulfone derivatives,-   viii nitrobenzylsulfonate derivatives, and-   ix sulfonate ester derivatives,

wherein R^(101a), R^(101b), and R^(101c) represents a linear, branched,or cyclic alkyl group, alkenyl group, oxoalkyl group, or oxoalkenylgroup, each having 1 to 12 carbon atoms, an aryl group having 6 to 20carbon atoms, or an aralkyl or aryl oxoalkyl group having 7 to 12 carbonatoms, and part or all of hydrogen atoms in these groups may beoptionally substituted by an alkoxy group or the like; R^(101b) andR^(101c) may form a ring, and when they form the ring, R^(101b) andR^(101c) each represents an alkylene group having 1 to 6 carbon atoms;K⁻ represents a non-nucleophilic counter ion; R^(101d), R^(101e),R^(101f), and R^(101g) represent a hydrogen atom, or the groups whosedefinition is as same as that of R^(101a), R^(101b), and R^(101c);R^(101d) and R^(101e), and R^(101d), R^(101e), and R^(101f) may form aring, and when they form the ring, R^(101d) and R^(101e), and R^(101d),R^(101e), and R^(101f) represent an alkylene group having 3 to 10 carbonatoms, or a heteroaromatic ring having a nitrogen atom in the ring ofthe formulae thereof.

R^(101a), R^(101b), R^(101c), R^(101d), R^(101e), R^(101f), and R^(101g)may be the same or different with each other, wherein specific examplethereof includes, as the alkyl group, a methyl group, an ethyl group, apropyl group, an isopropyl group, a n-butyl group, a sec-butyl group, atert-butyl group, a pentyl group, a hexyl group, a heptyl group, anoctyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptylgroup, a cyclopropylmethyl group, a 4-methylcyclohexyl group, acyclohexylmethyl group, a norbornyl group, and an adamantyl group.Illustrative example of the alkenyl group includes a vinyl group, anallyl group, a propenyl group, a butenyl group, a hexenyl group, and acyclohexenyl group. Illustrative example of the oxoalkyl group includesa 2-oxocyclopentyl group and a 2-oxocyclohexyl group, as well as a2-oxopropyl group, a 2-cyclopentyl-2-oxoethyl group, a2-cyclohexyl-2-oxoethyl group, and a 2-(4-methylcyclohexyl)-2-oxoethylgroup. Illustrative example of the oxoalkenyl group includes a2-oxo-4-cyclohexenyl group and a 2-oxo-4-propenyl group. Illustrativeexample of the aryl group includes a phenyl group, a naphthyl group, andthe like; alkoxyphenyl groups such as a p-methoxyphenyl group, am-methoxyphenyl group, an o-methoxyphenyl group, an ethoxyphenyl group,a p-tert-butoxyphenyl group, and a m-tert-butoxyphenyl group;alkylphenyl groups such as a 2-methylphenyl group, a 3-methylphenylgroup, a 4-methylphenyl group, an ethylphenyl group, a4-tert-butylphenyl group, a 4-butylphenyl group, and a dimethylphenylgroup; alkylnaphthyl groups such as a methylnaphthyl group and anethylnaphthyl group; alkoxynaphthyl groups such as a methoxynaphthylgroup and an ethoxynaphthyl group; dialkylnaphthyl groups such as adimethylnaphthyl group and a diethylnaphthyl group; and dialkoxynaphthylgroups such as a dimethoxynaphthyl group and a diethoxynaphthyl group.Illustrative example of the aralkyl group includes a benzyl group, aphenyletyl group, and a phenetyl group. Illustrative example of the aryloxoalkly group includes 2-aryl-2-oxoethyl groups such as a2-phenyl-2-oxoethyl group, a 2-(1-naphtyl)-2-oxoethyl group, and a2-(2-naphtyl)-2-oxoethyl group. Illustrative example of thenon-nucleophilic counter ion K⁻ includes halide ions such as a chlorideion and a bromide ion; fluoroalkyl sulfonates such as triflate,1,1,1-trifluoroethane sulfonate, and nonafluorobutane sulfonate;arylsulfonates such as tosylate, benzene sulfonate, 4-fluorobenzenesulfonate, and 1,2,3,4,5-pentafluorobenzene sulfonate; alkylsulfonatessuch as mesylate and butane sulfonate; imidic acids such asbis(trifluoromethylsulfonyl)imide, bis(perfluoroethylsulfonyl)imide, andbis(perfluorobutylsulfonyl)imide; methidic acids such astris(trifluoromethylsulfonyl)methide andtris(perfluoroethylsulfonyl)methide; and sulfonates such as thesulfonate whose α-position is substituted by fluorine as illustrated inthe following general formula (K-1) and the sulfonate whose α-positionand β-position are substituted by fluorine as illustrated in thefollowing general formula (K-2),

In the general formula (K-1), R^(102k) represents a hydrogen atom, or alinear, branched, or cyclic, alkyl or acyl group, each having 1 to 20carbon atoms, or an alkenyl group having 2 to 20 carbon atoms, or anaryl group or aryloxy group, each having 6 to 20 carbon atoms. In thegeneral formula (K-2), R^(103k) represents a hydrogen atom, or a linear,branched, or cyclic alkyl group having 1 to 20 carbon atoms, or analkenyl group having 2 to 20 carbon atoms, or an aryl group having 6 to20 carbon atoms.

Illustrative example of the heteroaromatic ring in which R^(101d),R^(101e), R^(101f), and R^(101g) have a nitrogen atom in the formula inthe ring includes imidazole derivatives (for example, imidazole,4-methylimidazole, and 4-methyl-2-phenylimidazole), pyrazolederivatives, furazan derivatives, pyrroline derivatives (for example,pyrroline and 2-methyl-1-pyrroline), pyrrolidine derivatives (forexample, pyrrolidine, N-methylpyrrolidine, pyrrolidinone, andN-methylpyrrolidone), imidazoline derivatives, imidazolidinederivatives, pyridine derivatives (for example, pyridine,methylpyridine, ethylpyridine, propylpyridine, butylpyridine,4-(1-butylpentyl)pyridine, dimethylpyridine, trimethylpyridine,triethylpyridine, phenylpyridine, 3-methyl-2-phenylpyridine,4-tert-butylpyridine, diphenylpyridine, benzylpyridine, methoxypyridine,butoxypyridine, dimethoxypyridine, 1-methyl-2-pyridone,4-pyrrolidinopyridine, 1-methyl-4-phenylpyridine,2-(1-ethylpropyl)pyridine, aminopyridine, and dimethylaminopyridine),pyridazine derivatives, pyrimidine derivatives, pyrazine derivatives,pyrazoline derivatives, pyrazolidine derivatives, piperidinederivatives, piperazine derivatives, morpholine derivatives, indolederivatives, isoindole derivatives, 1H-indazole derivatives, indolinederivatives, quinoline derivatives (for example, quinoline and3-quinoline carbonitrile), isoquinoline derivatives, cinnolinederivatives, quinazoline derivatives, quinoxaline derivatives,phthalazine derivatives, purine derivatives, pteridine derivatives,carbazole derivatives, phenanthridine derivatives, acridine derivatives,phenazine derivatives, 1,10-phenanthroline derivatives, adeninederivatives, adenosine derivatives, guanine derivatives, guanosinederivatives, uracil derivatives, and uridine derivatives.

(Pla-1) and (Pla-2) have both effects of the acid generator by light andthe acid generator by heat; but (Pla-3) acts as the acid generator byheat.

In the above general formula, R^(102a) and R^(102b) each represents alinear, branched, or cyclic alkyl group having 1 to 8 carbon atoms. R¹⁰³represents a linear, branched, or cyclic alkylene group having 1 to 10carbon atoms. R^(104a) and R^(104b) each represents a 2-oxoalkyl grouphaving 3 to 7 carbon atoms. The ion K⁻ represents a non-nucleophiliccounter ion.

Specific example of the alkyl group of R^(102a) and R^(102b) includes amethyl group, an ethyl group, a propyl group, an isopropyl group, an-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, ahexyl group, a heptyl group, an octyl group, a cyclopentyl group, acyclohexyl group, a cyclopropylmethyl group, a 4-methylcyclohexyl group,and a cyclohexylmethyl group. Specific example of the alkylene group ofR¹⁰³ includes a methylene group, an ethylene group, a propylene group, abutylene group, a pentylene group, a hexylene group, a heptylene group,an octylene group, a nonylene group, a 1,4-cyclohexylene group, a1,2-cyclohexylene group, a 1,3-cyclopentylene group, a 1,4-cyclooctylenegroup, and a 1,4-cyclohexane dimethylene group. Specific example of the2-oxoalkyl group of R^(104a) and R^(104b) includes a 2-oxopropyl group,a 2-oxocyclopentyl group, a 2-oxocyclohexyl group, and a2-oxocycloheptyl group. Illustrative example of K⁻ includes the sameions as those explained in the formulae (Pla-1), (Pla-2), and (Pla-3).

In the above general formula, R¹⁰⁵ and R¹⁰⁶ represent a linear,branched, or cyclic, alkyl or halogenated alkyl group having 1 to 12carbon atoms, or an aryl or halogenated aryl group having 6 to 20 carbonatoms, or an aralkyl group having 7 to 12 carbon atoms.

Illustrative example of the alkyl group of R¹⁰⁵ and R¹⁰⁶ includes amethyl group, an ethyl group, a propyl group, an isopropyl group, an-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, ahexyl group, a heptyl group, an octyl group, an amyl group, acyclopentyl group, a cyclohexyl group, a cycloheptyl group, a norbornylgroup, and an adamantyl group. Illustrative example of the halogenatedalkyl group includes a trifluoromethyl group, a 1,1,1-trifluoroethylgroup, a 1,1,1-trichloroethyl group, and a nonafluorobutyl group.Illustrative example of the aryl group includes a phenyl group;alkoxyphenyl groups such as a p-methoxyphenyl group, a m-methoxyphenylgroup, an o-methoxyphenyl group, an ethoxyphenyl group, ap-tert-butoxyphenyl group, and a m-tert-butoxyphenyl group; alkylphenylgroups such as a 2-methylphenyl group, a 3-methylphenyl group, a4-methylphenyl group, an ethylphenyl group, a 4-tert-butylphenyl group,a 4-butylphenyl group, and a dimethylphenyl group. Illustrative exampleof the halogenated aryl group includes a fluorophenyl group, achlorophenyl group, and a 1,2,3,4,5-pentafluorophenyl group.Illustrative example of the aralkyl group includes a benzyl group and aphenetyl group.

In the above general formula, R¹⁰⁷, R¹⁰⁸, and R¹⁰⁹ represent a linear,branched, or cyclic, alkyl or halogenated alkyl group, each having 1 to12 carbon atoms, or an aryl or halogenated aryl group having 6 to 20carbon atoms, or an aralkyl group having 7 to 12 carbon atoms. R¹⁰⁸ andR¹⁰⁹ may be bonded to each other to form a cyclic structure; and whenthe cyclic structure is formed, R¹⁰⁸ and R¹⁰⁹ represent a linear orbranched alkylene group having 1 to 6 carbon atoms. R¹⁰⁵ represents thesame as those in the formula (P2).

The alkyl group, the halogenated alkyl group, the aryl group, thehalogenated aryl group, and the aralkyl group of R¹⁰⁷, R¹⁰⁸, and R¹⁰⁹are the same as those explained in R¹⁰⁵ and R¹⁰⁶. Meanwhile,illustrative example of the alkylene group of R¹⁰⁸ and R¹⁰⁹ includes amethylene group, an ethylene group, a propylene group, a butylene group,and a hexylene group.

In the above general formula, R^(101a) and R^(101b) represent the sameas before.

In the above general formula, R¹¹⁰ represents an arylene group having 6to 10 carbon atoms, an alkylene group having 1 to 6 carbon atoms, or analkenylene group having 2 to 6 carbon atoms, wherein part or all of thehydrogen atoms of these groups may be further substituted by a linear orbranched alkyl or alkoxy group having 1 to 4 carbon atoms, a nitrogroup, an acetyl group, or a phenyl group. R¹¹¹ represents a linear,branched, or substituted alkyl, alkenyl, or alkoxyalkyl group having 1to 8 carbon atoms, a phenyl group, or a naphthyl group, wherein part orall of the hydrogen atoms in these groups may be further substituted byan alkyl or alkoxy group having 1 to 4 carbon atoms; or a phenyl groupoptionally substituted by an alkyl or alkoxy group having 1 to 4 carbonatoms, a nitro group, or an acetyl group; or a heteroaromatic grouphaving 3 to 5 carbon atoms; or a chlorine atom or a fluorine atom.

Here, illustrative example of R¹¹⁰ includes, as the arylene group, a1,2-phenylene group and 1,8-naphthylene group; as the alkylene group, amethylene group, an ethylene group, a trimethylene group, atetramethylene group, a phenylethylene group, and a norbornane-2,3-diylgroup; and as the alkenylene group, a 1,2-vinylene group, a1-phenyl-1,2-vinylene group, and a 5-norbornene-2,3-diyl group. In R¹¹¹,the alkyl group represents the same as those of R^(101a) to R^(101c),while illustrative example of the alkenyl group includes a vinyl group,a 1-propenyl group, an allyl group, a 1-butenyl group, a 3-butenylgroup, an isoprenyl group, a 1-pentenyl group, a 3-pentenyl group, a4-pentenyl group, a dimethylallyl group, a 1-hexenyl group, a 3-hexenylgroup, a 5-hexenyl group, a 1-heptenyl group, a 3-heptenyl group, a6-heptenyl group, and a 7-octenyl group; illustrative example of thealkoxyalkyl group includes a methoxymethyl group, an ethoxymethyl group,a propoxymethyl group, a butoxymethyl group, a pentyloxymethyl group, ahexyloxymethyl group, a heptyloxymethyl group, a methoxyethyl group, anethoxyethyl group, a propoxyethyl group, a butoxyethyl group, apentyloxyethyl group, a hexyloxyethyl group, a methoxypropyl group, anethoxypropyl group, a propoxypropyl group, a butoxypropyl group, amethoxybutyl group, an ethoxybutyl group, a propoxybutyl group, amethoxypentyl group, an ethoxypentyl group, a methoxyhexyl group, and amethoxyheptyl group.

Meanwhile, illustrative example of the optionally substituted alkylgroup having 1 to 4 carbon atoms includes a methyl group, an ethylgroup, a propyl group, an isopropyl group, a n-butyl group, an isobutylgroup, and a tert-butyl group; illustrative example of the alkoxy grouphaving 1 to 4 carbon atoms includes a methoxy group, an ethoxy group, apropoxy group, an isopropoxy group, a n-butoxy group, an isobutoxygroup, and a tert-butoxy group; illustrative example of the phenyl groupoptionally substituted with an alkyl group having 1 to 4 carbon atoms,an alkoxy group, a nitro group, or an acetyl group includes a phenylgroup, a tollyl group, a p-tert-butoxyphenyl group, a p-acetylphenylgroup, and a p-nitrophenyl group; and illustrative example of theheteroaromatic group having 3 to 5 carbon atoms includes a pyridyl groupand a furyl group.

With regard to the acid generator, illustrative example of the oniumsalt includes tetramethyl ammonium trifluoromethane sulfonate,tetramethyl ammonium nonafluorobutane sulfonate, triethyl ammoniumnonafluorobutane sulfonate, pyridinium nonafluorobutane sulfonate,triethyl ammonium camphor sulfonate, pyridinium camphor sulfonate,tetra-n-butyl ammonium nonafluorobutane sulfonate, tetraphenyl ammoniumnonafluorobutane sulfonate, tetramethyl ammonium p-toluene sulfonate,diphenyl iodonium trifluoromethane sulfonate, (p-tert-butoxyphenyl)phenyl iodonium trifluoromethane sulfonate, diphenyl iodonium p-toluenesulfonate, (p-tert-butoxyphenyl)phenyl iodonium p-toluene sulfonate,triphenylsulfonium trifluoromethane sulfonate, (p-tert-butoxyphenyl)diphenyl sulfonium trifluoromethane sulfonate,bis(p-tert-butoxyphenyl)phenyl sulfonium trifluoromethane sulfonate,tris(p-tert-butoxyphenyl) sulfonium trifluoromethane sulfonate,triphenyl sulfonium p-toluene sulfonate, (p-tert-butoxyphenyl) diphenylsulfonium p-toluene sulfonate, bis(p-tert-butoxyphenyl) phenyl sulfoniump-toluene sulfonate, tris(p-tert-butoxyphenyl) sulfonium p-toluenesulfonate, triphenyl sulfonium nonafluorobutane sulfonate, triphenylsulfonium butanesulfonate, trimethyl sulfonium trifluoromethanesulfonate, trimethyl sulfonium p-toluene sulfonate,cyclohexylmethyl(2-oxocyclohexyl) sulfonium trifluoromethane sulfonate,cyclohexylmethyl(2-oxocyclohexyl) sulfonium p-toluene sulfonate,dimethylphenyl sulfonium trifluoromethane sulfonate, dimethylphenylsulfonium p-toluene sulfonate, dicyclohexylphenyl sulfoniumtrifluoromethane sulfonate, dicyclohexylphenyl sulfonium p-toluenesulfonate, trinaphthyl sulfonium trifluoromethane sulfonate,(2-norbonyl)methyl(2-oxocyclohexyl) sulfonium trifluoromethanesulfonate, ethylene bis[methyl(2-oxocyclopentyl) sulfoniumtrifluoromethane sulfonate], 1,2′-naphthalenecarbonylmethyltetrahydrothiophenium triflate, triethyl ammonium nonaflate, tributylammonium nonaflate, tetraethyl ammonium nonaflate, tetrabutyl ammoniumnonaflate, triethyl ammonium bis(trifluoromethylsulfonyl)imide, andtriethyl ammonium tris(perfluoroethylsulfonyl)methide.

Illustrative example of the diazomethane derivative includesbis(benzenesulfonyl) diazomethane, bis(p-toluenesulfonyl) diazomethane,bis(xylenesulfonyl) diazomethane, bis(cyclohexylsulfonyl) diazomethane,bis(cyclopentylsulfonyl) diazomethane, bis(n-butylsulfonyl)diazomethane, bis(isobutylsulfonyl) diazomethane, bis(sec-butylsulfonyl)diazomethane, bis(n-propylsulfonyl) diazomethane, bis(isopropylsulfonyl)diazomethane, bis(tert-butylsulfonyl) diazomethane, bis(n-amylsulfonyl)diazomethane, bis(isoamylsulfonyl) diazomethane, bis(sec-amylsulfonyl)diazomethane, bis(tert-amylsulfonyl) diazomethane,1-cyclohexylsulfonyl-1-(tert-butylsulfonyl) diazomethane,1-cyclohexylsulfonyl-1-(tert-amylsulfonyl) diazomethane, and1-tert-amylsulfonyl-1-(tert-butylsulfonyl) diazomethane.

Illustrative example of the glyoxime derivative includesbis-O-(p-toluenesulfonyl)-α-dimethyl glyoxime,bis-O-(p-toluenesulfonyl)-α-diphenyl glyoxime,bis-O-(p-toluenesulfonyl)-α-dicyclohexyl glyoxime,bis-O-(p-toluenesulfonyl)-2,3-pentanedion glyoxime,bis-O-(p-toluenesulfonyl)-2-methyl-3,4-pentanedion glyoxime,bis-O-(n-butanesulfonyl)-α-dimethyl glyoxime,bis-O-(n-butanesulfonyl)-α-diphenyl glyoxime,bis-O-(n-butanesulfonyl)-α-dicyclohexyl glyoxime,bis-O-(n-butanesulfonyl)-2,3-pentanedion glyoxime,bis-O-(n-butanesulfonyl)-2-methyl-3,4-pentanedion glyoxime,bis-O-(methanesulfonyl)-α-dimethyl glyoxime,bis-O-(trifluoromethanesulfonyl)-α-dimethyl glyoxime,bis-O-(1,1,1-trifluoroethanesulfonyl)-α-dimethyl glyoxime,bis-O-(tert-butanesulfonyl)-α-dimethyl glyoxime,bis-O-(perfluoroctanesulfonyl)-α-dimethyl glyoxime,bis-O-(cyclohexanesulfonyl)-α-dimethyl glyoxime,bis-O-(benzenesulfonyl)-α-dimethyl glyoxime,bis-O-(p-fluorobenzenesulfonyl)-α-dimethyl glyoxime,bis-O-(p-tert-butylbenzenesulfonyl)-α-dimethyl glyoxime,bis-O-(xylenesulfonyl)-α-dimethyl glyoxime, andbis-O-(camphorsulfonyl)-α-dimethyl glyoxime.

Illustrative example of the bissulfone derivative includes bisnaphthylsulfonyl methane, bistrifuloromethyl sulfonyl methane, bismethylsulfonyl methane, bisethyl sulfonyl methane, bispropyl sulfonyl methane,bisisopropyl sulfonyl methane, bis-p-toluene sulfonyl methane, andbisbenzene sulfonyl methane.

Illustrative example of the β-ketosulfone derivative includes2-cyclohexylcarbonyl-2-(p-toluenesulfonyl) propane and2-isopropylcarbonyl-2-(p-toluenesulfonyl) propane.

Illustrative example of the disulfone derivative includes diphenyldisulfone derivatives and dicyclohexyl disulfone derivatives.

Illustrative example of the nitrobenzyl sulfonate derivative includes2,6-dinitrobenzyl p-toluene sulfonate and 2,4-dinitrobenzyl p-toluenesulfonate.

Illustrative example of the sulfonate ester derivative includes1,2,3-tris(methanesulfonyloxy)benzene,1,2,3-tris(trifuoromethanesulfonyloxy)benzene, and1,2,3-tris(p-toluenesulfonyloxy)benzene.

Illustrative example of the sulfonate ester derivative of anN-hydroxyimide compound includes N-hydroxysuccinimide methane sulfonateester, N-hydroxysuccinimide trifuloromethane sulfonate ester,N-hydroxysuccinimide ethane sulfonate ester, N-hydroxysuccinimide1-propane sulfonate ester, N-hydroxysuccinimide 2-propane sulfonateester, N-hydroxysuccinimide 1-pentane sulfonate ester,N-hydroxysuccinimide 1-octane sulfonate ester, N-hydroxysuccinimidep-toluene sulfonate ester, N-hydroxysuccinimide p-methoxybenzenesulfonate ester, N-hydroxysuccinimide 2-chlroethane sulfonate ester,N-hydroxysuccinimide benzene sulfonate ester,N-hydroxysuccinimide-2,4,6-trimethylbenzene sulfonate ester,N-hydroxysuccinimide 1-naphthalene sulfonate ester, N-hydroxysuccinimide2-naphthalene sulfonate ester, N-hydroxy-2-phenylsuccinimide methanesulfonate ester, N-hydroxymaleimide methane sulfonate ester,N-hydroxymaleimide ethane sulfonate ester, N-hydroxy-2-phenylmaleimidemethane sulfonate ester, N-hydroxygultarimide methane sulfonate ester,N-hydroxygultarimide benzene sulfonate ester, N-hydroxyphthalimidemethane sulfonate ester, N-hydroxyphthalimide benzene sulfonate ester,N-hydroxyphthalimide trifluoromethane sulfonate ester,N-hydroxyphthalimide p-toluene sulfonate ester, N-hydroxynaphthalimidemethane sulfonate ester, N-hydroxynaphthalimide benzene sulfonate ester,N-hydroxy-5-norbornene-2,3-dicarboxyimide methane sulfonate ester,N-hydroxy-5-norbornene-2,3-dicarboxyimide trifluoromethane sulfonateester, and N-hydroxy-5-norbornene-2,3-dicarboxyimide p-toluene sulfonateester.

Among them, especially preferably used acid generators are as follows:onium salts such as triphenyl sulfonium trifluoromethane sulfonate,(p-tert-butoxyphenyl) diphenyl sulfonium trifluoromethane sulfonate,tris(p-tert-butoxyphenyl) sulfonium trifluoromethane sulfonate,triphenyl sulfonium p-toluene sulfonate, (p-tert-butoxyphenyl) diphenylsulfonium p-toluene sulfonate, tris(p-tert-butoxyphenyl) sulfoniump-toluene sulfonate, trinaphthyl sulfonium trifluoromethane sulfonate,cyclohexyl methyl (2-oxocyclohexyl) sulfonium trifluoromethanesulfonate, (2-norbornyl) methyl (2-oxocyclohexyl) sulfoniumtrifluoromethane sulfonate, and 1,2′-naphthalenecarbonylmethyltetrahydrothiophenium triflate; diazomethane derivatives such asbis(benzenesulfonyl) diazomethane, bis(p-toluenesulfonyl) diazomethane,bis(cyclohexylsulfonyl) diazomethane, bis(n-butylsulfonyl) diazomethane,bis(isobutylsulfonyl) diazomethane, bis(sec-butylsulfonyl) diazomethane,bis(n-propylsulfonyl) diazomethane, bis(isopropylsulfonyl) diazomethane,and bis(tert-butylsulfonyl) diazomethane; glyoxime derivatives such asbis-O-(p-toluenesulfonyl)-α-dimethyl glyoxime andbis-O-(n-butanesulfonyl)-α-dimethyl glyoxime; bissulfone derivativessuch as bisnaphthyl sulfonyl methane; and sulfonate ester derivatives ofan N-hydroxyimide compound such as N-hydroxysuccinimide methanesulfonate ester, N-hydroxysuccinimide trifluoromethane sulfonate ester,N-hydroxysuccinimide 1-propane sulfonate ester, N-hydroxysuccinimide2-propane sulfonate ester, N-hydroxysuccinimide 1-pentane sulfonateester, N-hydroxysuccinimide p-toluene sulfonate ester,N-hydroxynaphthalimide methane sulfonate ester, andN-hydroxynaphthalimide benzene sulfonate ester.

Meanwhile, the acid generator mentioned above can be used singly or as acombination of two or more of them. Addition amount of the acidgenerator is preferably in the range of 0.05 to 50 parts by mass, whilemore preferably in the range of 0.1 to 10 parts by mass, relative to 100parts by mass of the base resin. When the addition amount is 0.05 partsby mass or more, a risk of insufficient crosslinking reaction due tosmall amount of acid generation can be reduced; and when the additionamount is 50 parts by mass or less, a risk of causing a mixingphenomenon due to migration of the acid to the upper resist layers canbe avoided.

[(D) Component]

The resist underlayer film composition of the present invention may beblended with (D) surfactant in order to improve applicability thereof inspin coating. Illustrative example of the usable surfactant includesthose described in the paragraphs [0142] to [0147] of Japanese PatentLaid-Open Publication No. 2009-269953.

[(E) Component]

The resist underlayer film composition of the present invention may alsobe blended with (E) crosslinking agent in order to enhance thecurability and further suppress the intermixing with the upper layerfilms. There is no particular restriction in the crosslinking agent, sothat heretofore known crosslinking agents with various types may bewidely used. Illustrative example thereof includes a melamine-typecrosslinking agent, a glycoluril-type crosslinking agent, abenzoguanamine-type crosslinking agent, a urea-type crosslinking agent,a β-hydroxyalkylamide-type crosslinking agent, an isocyanurate-typecrosslinking agent, an aziridine-type crosslinking agent, anoxazoline-type crosslinking agent, and an epoxy-type crosslinking agent.

Specific example of the melamine-type crosslinking agent includeshexamethoxymethylated melamine, hexabutoxymethylated melamine, as wellas an alkoxy-and/or hydroxy-substituted compound thereof and partialself-condensed compound thereof. Specific example of the glycoluril-typecrosslinking agent includes tetramethoxymethylated glycoluril,tetrabutoxymethylated glycoluril, as well as an alkoxy- and/orhydroxy-substituted compound thereof and partial self-condensed compoundthereof. Specific example of the benzoguanamine-type crosslinking agentincludes tetramethoxymethylated benzoguanamine, tetrabutoxymethylatedbenzoguanamine, as well as an alkoxy- and/or hydroxy-substitutedcompound thereof and partial self-condensed compound thereof. Specificexample of the urea-type crosslinking agent includes dimethoxymethylateddimethoxy ethylene urea, as well as an alkoxy- and/orhydroxy-substituted compound thereof and partial self-condensed compoundthereof. Specific example of the β-hydroxyalkylamide-type crosslinkingagent includes N,N,N′,N′-tetra(2-hydroxyethyl)adipic amide. Specificexample of the isocyanurate-type crosslinking agent includes triglycidylisocyanurate and trially isocyanurate. Specific example of theaziridine-type crosslinking agent includes4,4′-bis(ethyleneiminocarbonylamino) diphenylmethane and2,2-bishydroxymethylbutanol tris[3-(1-aziridinyl)propionate]. Specificexample of the oxazoline-type crosslinking agent includes2,2′-isopropylidene bis(4-benzyl-2-oxazoline), 2,2′-isopropylidenebis(4-phenyl-2-oxazoline), 2,2′-methylene bis 4,5-diphenyl-2-oxazoline,2,2′-methylene bis-4-phenyl-2-oxazoline, 2,2′-methylene bis4-tert-butyl-2-oxazoline, 2,2′-bis(2-oxazoline), 1,3-phenylenebis(2-oxazoline), 1,4-phenylene bis(2-oxazoline), and 2-isopropenyloxazoline copolymer. Specific example of the epoxy-type crosslinkingagent includes diglycidyl ether, ethyleneglycol diglycidyl ether,1,4-butanediol diglycidyl ether, 1,4-cyclohexane dimethanol diglycidylether, poly(methacrylate diglycidyl), trimethylolethane triglycidylether, trimethylolpropane triglycidyl ether, and pentaerythritoltetraglycidyl ether.

[(F) Component]

The resist underlayer film composition of the present invention may beblended with (F) plasticizer in order to further improve theplanarization and gap-filing characteristics. There is no particularrestriction in the plasticizer, so that heretofore known plasticizers ofvarious types may be widely used. Illustrative example thereof includeslow molecular weight compounds such as phthalate esters, adipate esters,phosphate esters, trimellitate esters, and citrate esters, as well aspolymers such as polyethers, polyesters, and polyacetals described inJapanese Patent Laid-Open Publication No. 2013-253227.

[(G) Component]

The resist underlayer film composition of the present invention may beblended with (G) pigment in order to further improve the resolution uponpatterning of the multilayer lithography. There is no particularrestriction in the pigment so far as it is the compound having anappropriate absorbance in the irradiation wavelength, so that variousheretofore known compounds can be widely used. Illustrative examplethereof includes benzenes, naphthalenes, anthracenes, phenanthrenes,pyrenes, isocyanuric acids, and triazines.

It is preferable that the resist underlayer film composition of thepresent invention can give the resist underlayer film exhibiting theresistance to the ammonia-containing hydrogen peroxide aqueous solution.The resist underlayer film composition as mentioned above can form theresist underlayer film which is excellent in the resistance to the basichydrogen peroxide aqueous solution, so that this composition can also beused in the wet etching process using the basic hydrogen peroxideaqueous solution.

The basic hydrogen peroxide aqueous solution is generally used incleaning of a semiconductor wafer. Especially, a mixture of 5 parts bymass of deionized water, 1 parts by mass of 29% by mass of aqueousammonia solution, and 1 parts by mass of 30% by mass of hydrogenperoxide aqueous solution is called as SC1 (Standard Clean-1); and thismixture becomes a standard chemical solution for rinsing to removeorganic impurities and microparticles on the wafer surface. In addition,by the basic hydrogen peroxide aqueous solution, delamination or etchingprocessing is possible not only for some metals and metal compounds butalso for a silicon-containing resist intermediate film that is designedfor wet delamination. The composition of the basic hydrogen peroxideaqueous solution is not particularly restricted; however, typically thisis a mixture of deionized water, hydrogen peroxide, and ammonia. In thiscase, concentration of hydrogen peroxide is preferably in the range of0.1 to 10% by mass, while more preferably in the range of 0.2 to 5% bymass; and concentration of ammonia is preferably in the range of 0.1 to10% by mass, while more preferably in the range of 0.2 to 5% by mass.The temperature in the processing is preferably in the range of 0 to 90°C., while more preferably in the range of 20 to 80° C.

Meanwhile, the test of the resistance to the basic hydrogen peroxideaqueous solution of the resist underlayer film will be explained. Atfirst, under the coating conditions to be mentioned later, onto asilicon wafer which is cut to the size of 3 cm square the resistunderlayer film composition is applied so as to give the film thicknessof about 100 nm. Thereafter, this wafer piece is soaked in the 1.0% bymass hydrogen peroxide aqueous solution containing 0.5% by mass ofammonia at 70° C. for 2 minutes or at 70° C. for 5 minutes, and then,this is rinsed with deionized water; thereafter, whether or not theresist underlayer film is delaminated from the wafer can be examinedvisually. When part or all of the resist underlayer film is delaminatedthereby exposing the silicon wafer surface, the resist underlayer filmsubjected to the test is judged to be insufficient in the resistance tothe basic hydrogen peroxide aqueous solution.

Namely, in the resist underlayer film formed by the resist underlayerfilm composition of the present invention, it is preferable thatdelamination of the resist underlayer film be not observed upon soakingthe silicon substrate formed with this resist underlayer film in the1.0% by mass hydrogen peroxide aqueous solution containing 0.5% by massof ammonia at 70° C. for 5 minutes.

Meanwhile, in the present invention, thickness of the resist underlayerfilm can be arbitrarily chosen; however, the thickness is preferably inthe range of 30 to 20,000 nm, while especially preferably in the rangeof 50 to 15,000 nm. In the case of the resist underlayer film for athree-layer resist process, a silicon-containing resist intermediatefilm may be formed on the resist underlayer film, and on theintermediate film, the resist upper layer film not containing a siliconmay be formed. In the case of the resist underlayer film for a two-layerresist process, a resist upper layer film containing a silicon, or aresist upper layer film not containing a silicon may be formed on theresist underlayer film.

(Method for Forming the Resist Underlayer Film)

In the present invention the method for forming the resist underlayerfilm is provided, wherein the resist underlayer film compositionmentioned above is applied onto the substrate to be processed; and then,the resist underlayer film composition is subjected to the heattreatment in the temperature 100° C. or more and 300° C. or less, bothends inclusive, in the time range of 10 to 600 seconds to form a curedfilm.

In the method of the present invention for forming the resist underlayerfilm, the resist underlayer film composition mentioned above is appliedonto the substrate to be processed by using a spin coating method or thelike; and then, after the solvent is evaporated, baking is carried outin order to prevent the mixing with the resist upper layer film and theresist intermediate film, or to facilitate the crosslinking reaction.When the application thereof is made by a spin coating method or thelike, the excellent gap-filling characteristic can be obtained.

The baking is carried out in the temperature 100° C. or more and 300° C.or less, both ends inclusive, while preferably 150° C. or more and 280°C. or less, both ends inclusive, and in the time range of 10 to 600seconds, while preferably in the range of 10 to 300 seconds. When thebaking temperature and time are appropriately controlled within theranges mentioned above, the planarization and gap-fillingcharacteristics as well as curing characteristic suitable for the usecan be obtained. When the baking temperature is 100° C. or more,sufficient cure can be obtained, so that there is no risk of mixing withthe upper layer film or the intermediate film. When the bakingtemperature is 300° C. or less, thermal decomposition of the base resinis not significant, so that there is no risk of decrease in the filmthickness or to cause uneven film surface.

In the method of the present invention for forming the resist underlayerfilm, as the substrate to be processed, it is preferable also to use thesubstrate having the structural body with the height of 30 nm or more,or having the step. The method of the present invention for forming theresist underlayer film is especially useful for forming the planarizedorganic film without voids on the substrate having the structural bodywith the height of 30 nm or more, or having the step.

(Patterning Process)

In the present invention, the patterning process using the resistunderlayer film composition mentioned above is provided. The patterningprocess of the present invention can be suitably used in multilayerresist processes such as a silicon-containing two-layer resist process,a three-layer resist process using a silicon-containing intermediatefilm, a four-layer resist process using a silicon-containingintermediate film and an organic antireflective film, or a two-layerresist process not containing a silicon.

Namely, the present invention provides a patterning process, wherein thepatterning process is to form a pattern on a substrate to be processedas a two-layer resist process and comprises:

-   (I-1) forming a resist underlayer film on the substrate to be    processed by using the resist underlayer film composition,-   (I-2) forming a resist upper layer film on the resist underlayer    film by using a photoresist composition,-   (I-3) forming a pattern on the resist upper layer film by developing    the resist upper layer film by using a developer after the resist    upper layer film is pattern-exposed, and-   (I-4) transcribing the pattern to the resist underlayer film by dry    etching using as a mask the resist upper layer film formed with the    pattern.

In addition, the present invention provides a patterning process,wherein the patterning process is to form a pattern on a substrate to beprocessed as a three-layer resist process and comprises:

-   (II-1) forming a resist underlayer film on the substrate to be    processed by using the resist underlayer film composition,-   (II-2) forming a resist intermediate film on the resist underlayer    film,-   (II-3) forming a resist upper layer film on the resist intermediate    film by using a photoresist composition,-   (II-4) forming a pattern on the resist upper layer film by    developing the resist upper layer film by using a developer after    the resist upper layer film is pattern-exposed,-   (II-5) transcribing the pattern to the resist intermediate film by    dry etching using as a mask the resist upper layer film formed with    the pattern, and-   (II-6) transcribing the pattern to the resist underlayer film by dry    etching using as a mask the resist intermediate film transcribed    with the pattern.

In addition, the present invention provides a patterning process,wherein the patterning process is to form a pattern on a substrate to beprocessed as a four-layer resist process and comprises:

-   (III-1) forming a resist underlayer film on the substrate to be    processed by using the resist underlayer film composition,-   (III-2) forming an inorganic hard mask intermediate film selected    from a silicon oxide film, a silicon nitride film, and a silicon    oxide nitride film on the resist underlayer film,-   (III-3) forming an organic antireflective film on the inorganic hard    mask intermediate film,-   (III-4) forming a resist upper layer film on the organic    antireflective film by using a photoresist composition,-   (III-5) forming a pattern on the resist upper layer film by    developing the resist upper layer film by using a developer after    the resist upper layer film is pattern-exposed,-   (III-6) transcribing the pattern to the organic antireflective film    and the inorganic hard mask intermediate film by dry etching using    as a mask the resist upper layer film formed with the pattern, and-   (III-7) transcribing the pattern to the resist underlayer film by    dry etching using as a mask the inorganic hard mask intermediate    film transcribed with the pattern.

Hereunder, the patterning process of the present invention will beexplained with regard to the three-layer resist process using a resistintermediate film containing a silicon atom (silicon-containing resistintermediate film) as an example; however, the present invention is notlimited to this.

In this case, a resist underlayer film is formed on a substrate to beprocessed by using the resist underlayer film composition; on thisresist underlayer film, a resist intermediate film is formed by using aresist intermediate film composition containing a silicon atom; furtheron the resist intermediate film, a resist upper layer film is formed byusing a photoresist composition to form a multilayer resist film; aftera pattern circuit region of the resist upper layer film is exposed to alight (pattern exposure), a pattern is formed on the resist upper layerfilm by development using a developer; the pattern is transcribed byetching the resist intermediate film by using as a mask the resist upperlayer film formed with the pattern; the pattern is transcribed byetching the resist underlayer film by using as a mask the resistintermediate film transcribed with the pattern; and further, the patternis formed on the substrate to be processed by processing the substrateto be processed by using as a mask the resist underlayer filmtranscribed with the pattern.

The resist underlayer film in the three-layer resist process can beformed in the way that the resist underlayer film composition is appliedonto the substrate to be processed by using a spin coating method or thelike, and then, after the solvent is evaporated, baking is carried outin order to prevent the mixing with the resist upper layer film and withthe resist intermediate film, or to facilitate a crosslinking reaction.When the composition is applied by a spin coating method or the like,the excellent gap-filling characteristic can be obtained.

The baking is carried out in the temperature 100° C. or more and 300° C.or less, both ends inclusive, while preferably in the range of 150° C.or more and 280° C. or less, both ends inclusive, and in the time rangeof 10 to 600 seconds, while preferably in the range of 10 to 300seconds. When the baking temperature and time are appropriatelycontrolled within the ranges mentioned above, the planarization andgap-filling characteristics as well as curing characteristic suitablefor the use can be obtained. When the baking temperature is 100° C. ormore, sufficient cure can be obtained, so that there is no risk ofmixing with the upper layer film or with the intermediate film. When thebaking temperature is 300° C. or less, thermal decomposition of the baseresin is not significant, so that there is no risk of decrease in thefilm thickness or to cause uneven film surface.

The resist intermediate film containing a silicon atom exhibits aresistance to etching by an oxygen gas or a hydrogen gas. Accordingly,etching of the resist underlayer film by using the resist intermediatefilm as a mask is carried out preferably by using an etching gas mainlycomprising an oxygen gas or a hydrogen gas.

For the silicon-containing resist intermediate film in the three-layerresist process, a polysilsesquioxane-based intermediate film can besuitably used. The polysilsesquioxane-based resist intermediate film canbe readily provided with an antireflective effect, so that a reflectedlight during pattern exposure of the resist upper layer film can besuppressed; and thus, this has an advantage of excellent resolution.Especially, for the exposure to a 193 nm light beam, the resistunderlayer film formed of the composition containing large amount of anaromatic group has a high k-value thereby leading to increase in thesubstrate reflection; however, because the reflection can be suppressedby the resist intermediate film, the substrate reflection can besuppressed to 0.5% or less. For the resist intermediate film having anantireflective effect, the polysilsesquioxane crosslinkable with an acidor a heat having an anthracene pendant is preferably used for exposureto a 248 nm or 157 nm light beam, while the polysilsesquioxanecrosslinkable by an acid or a heat having a pendant of a phenyl group ora light-absorbing group having a silicon-silicon bond is preferably usedfor exposure to a 193 nm light beam.

In this case, formation of the silicon-containing resist intermediatefilm by a spin coating method is more advantageous than a CVD method inview of convenience and cost.

With regard to the resist upper layer film in the three-layer resistprocess, whether a positive type or a negative type may be used, whereinthe same type as the photoresist composition usually used may be used.When the resist upper layer film is formed by the photoresistcomposition mentioned above, similarly to the case of forming the resistunderlayer film, the spin coating method is preferably used. After thephotoresist composition is applied by the spin coating method, apre-bake is carried out, wherein preferably the temperature thereof isin the range of 60 to 180° C. and the time thereof is in the range of 10to 300 seconds. Thereafter, by carrying out the exposure to a light in aconventional way, followed by the post exposure bake (PEB), and then bythe development, the resist pattern is obtained. Meanwhile, there is noparticular restriction in thickness of the resist upper layer film;however, the thickness is preferably in the range of 30 to 500 nm,especially in the range of 50 to 400 nm.

The exposure lights to be used are high energy beams with the wavelengthof 300 nm or less; and specific example thereof includes excimer laserbeams of 248 nm, 193 nm, and 157 nm; soft X-ray beams of 3 to 20 nm;electronic beams; and X-ray beams.

Next, etching is carried out by using the resist pattern thus obtainedas a mask. Etching of the resist intermediate film in the three-layerresist process is carried out with a freon-based gas by using the resistpattern as a mask. Next, the resist underlayer film is processed byetching using as a mask the pattern of the resist intermediate film withan oxygen gas or a hydrogen gas.

Etching of the substrate to be processed in the next step may be carriedout by a conventional method, for example, an etching with a gas mainlycomposed of a freon-based gas when the substrate is SiO₂, SiN, or asilica-based insulating film with a low dielectric constant, or anetching with a gas mainly composed of a chlorine-based gas or abromine-based gas when the substrate is p-Si, Al, or W. When thesubstrate processing is carried out by etching with a freon-based gas,the resist intermediate film (silicon-containing resist intermediatefilm) in the three-layer resist process is delaminated simultaneouslywith the substrate processing. When the substrate is etched with achlorine-based gas or a bromine-based gas, delamination of thesilicon-containing intermediate film needs to be carried out separatelyby dry etching with a freon-based gas after processing of the substrate.

Meanwhile, with regard to the substrate to be processed, a layer to beprocessed is formed on the substrate. There is no particular restrictionin the substrate, wherein a material different from the layer to beprocessed, such as Si, α-Si, p-Si, SiO₂, SiN, SiON, W, TiN, and Al, maybe used. With regard to the layer to be processed, various low-k filmssuch as Si, SiO₂, SiON, SiN, p-Si, α-Si, W, TiN, W—Si, Al, Cu, andAl—Si, as well as stopper films of them, and the like, may be used,wherein the layer is formed with the thickness of usually in the rangeof 50 to 10,000 nm, especially in the range of 100 to 5,000 nm.

Meanwhile, when the patterning process of the present invention is used,in addition to general manufacturing processes as mentioned above,various special manufacturing processes can be constructed; and thus,the patterning process of the present invention has a high value inindustry.

Firstly, with regard to delamination of the silicon-containing resistintermediate film, generally, delamination by the dry etching isimperative as mentioned above; however, in the patterning process of thepresent invention, because the resist underlayer film has the resistanceto the basic hydrogen peroxide aqueous solution, wet delamination ofonly the silicon-containing resist intermediate film by using the basichydrogen peroxide aqueous solution can also be chosen. Namely, in thepatterning process of the three-layer resist process of the presentinvention, a step of removing the resist intermediate film transcribedwith the pattern by the wet etching using the basic hydrogen peroxideaqueous solution may be further added after the step of (II-6) mentionedabove.

Further, in the case that the substrate to be processed is W, TiN or thelike, when the patterning process of the present invention is used, thewet etching processing of the substrate by using the basic hydrogenperoxide aqueous solution can also be chosen. Namely, in the patterningprocess of the two-layer, three-layer, four-layer resist processes ofthe present invention, a step of transcribing the pattern to thesubstrate to be processed by the wet etching using the basic hydrogenperoxide aqueous solution by using as a mask the resist underlayer filmtranscribed with the pattern may be further added after the step of(I-4), the step of (II-6), or the step of (III-7) mentioned above.

In one example of this case, firstly, the resist underlayer film isformed on the substrate to be processed, and if necessary, on it theresist intermediate film is formed, and then, the resist upper layerfilm is formed. Next, the resist upper layer film is patterned with aconventional method, and then, the pattern is transcribed to the resistunderlayer film by etching. Finally, the substrate to be processed canbe patterned by the wet etching using the resist underlayer film as amask.

In addition, in the patterning process of the two-layer, three-layer,and four-layer resist processes of the present invention, a patterningstep of the substrate to be processed by ion implantation using as amask the resist underlayer film transcribed with the pattern may beadded after the step of (I-4), the step of (II-6), or the step of(III-7). In this case, after the pattern processing step by the ionimplantation of the substrate to be processed, a step of removing theresist intermediate film transcribed with the pattern may be furtheradded, wherein this removal is carried out by the wet etching using thebasic hydrogen peroxide aqueous solution.

The patterning process of the present invention is also suitable forprocessing of the substrate having the structural body with the heightof 30 nm or more, or having the step. Hereunder, one example of suchprocess will be explained.

Firstly, the resist underlayer film is formed on the substrate havingsteps so as to carry out gap-filling and planarization; and then, afterthe resist intermediate film is formed if necessary, the resist upperlayer film is formed. Next, the resist upper layer film is patternedwith a conventional method, and then, the pattern is transcribed to theresist underlayer film by etching. Next, the substrate can bepattern-processed by the ion implantation using the resist underlayerfilm as a mask. Delamination of the remained resist intermediate filmcan be carried out by choosing the dry etching or the wet etching asappropriate. Finally, the resist underlayer film can be removed by thedry etching.

At this time, it is preferable to use the resist underlayer filmcomposition having the dry etching rate faster than the dry etching rateof the resist upper layer film. When the resist underlayer filmcomposition to form the film like this is used (namely, when the dryetching rate of the resist underlayer film to be formed is fast), eventhe resist underlayer film in the spot where the removal thereof isgenerally difficult, such as a corner of the steps of the substrate, canbe removed without residues by the dry etching; and thus, thecomposition as mentioned above is further preferable.

In addition, in the patterning process of the present invention, atleast, a resist underlayer film is formed on a substrate to be processedby using the resist underlayer film composition; on the resistunderlayer film, an inorganic hard mask intermediate film selected froma silicon oxide film, a silicon nitride film, and a silicon oxidenitride film is formed; further on the inorganic hard mask intermediatefilm, a resist upper layer film is formed by using a photoresistcomposition; after a pattern circuit region of the resist upper layerfilm is exposed to a light, a pattern is formed on the resist upperlayer film by development using a developer; the pattern is transcribedby etching the inorganic hard mask intermediate film by using as a maskthe resist upper layer film formed with the pattern; the pattern istranscribed by etching the resist underlayer film by using as a mask theinorganic hard mask intermediate film transcribed with the pattern; andthe pattern is formed on the substrate to be processed by processing thesubstrate to be processed by using as a mask the resist underlayer filmtranscribed with the pattern.

In the case that the inorganic hard mask intermediate film is formed onthe resist underlayer film as mentioned above, a silicon oxide film, asilicon nitride film, or a silicon oxide nitride film (SiON film) isformed by a CVD method, an ALD method, or the like. The method forforming the nitride film is described in Japanese Patent Laid-OpenPublication No. 2002-334869 and International Patent Laid-OpenPublication No. 2004/066377. Thickness of the inorganic hard maskintermediate film is in the range of 5 to 200 nm, while more preferablyin the range of 10 to 100 nm. Especially, the SiON film, which has ahigh effect as the antireflective film, is used most preferably.

In addition, the present invention can be suitably used in thefour-layer resist process using an organic antireflective film. In thiscase, at least, a resist underlayer film is formed on a substrate to beprocessed by using the resist underlayer film composition; on the resistunderlayer film, an inorganic hard mask intermediate film selected froma silicon oxide film, a silicon nitride film, and a silicon oxidenitride film is formed; on the inorganic hard mask intermediate film, anorganic antireflective film is formed; on the organic antireflectivefilm, a resist upper layer film is formed by using a photoresistcomposition; after a pattern circuit region of the resist upper layerfilm is exposed to a light, a pattern is formed on the resist upperlayer film by development using a developer; the pattern is transcribedby etching the organic antireflective film and the inorganic hard maskintermediate film by using as a mask the resist upper layer film formedwith the pattern; the pattern is transcribed by etching the resistunderlayer film by using as a mask the inorganic hard mask intermediatefilm transcribed with the pattern; and the pattern is formed on thesubstrate to be processed by processing the substrate to be processed byusing as a mask the resist underlayer film transcribed with the pattern.

It may be allowed to form the photoresist film as the resist upper layerfilm on the resist intermediate film; or alternatively, the organicantireflective film (BARC) may be formed on the resist intermediate filmby spin coating followed by forming the photoresist film on it. When aSiON film is used as the resist intermediate film, because of twoantireflective films of the SiON film and the BARC film, the reflectioncan be suppressed even in the immersion exposure with high NA of morethan 1.0. Formation of the BARC film has an additional merit, i.e., theeffect to decrease footing of the photoresist pattern immediately abovethe SiON film.

One example of the three-layer resist process will be specificallyexplained as follows by using FIG. 1.

In the case of the three-layer resist process, as depicted in FIG. 1(A),after the resist underlayer film 3 is formed on the layer to beprocessed 2 that is laminated on the substrate 1, the resistintermediate film 4 is formed, and then, on it the resist upper layerfilm 5 is formed.

Next, as depicted in FIG. 1(B), the prescribed portion 6 of the resistupper layer film is exposed to a light, and then, PEB (post-exposurebake) and development are carried out to form the resist pattern 5 a(FIG. 1(C)). By using as a mask the resist pattern 5 a thus obtained,the resist intermediate film 4 is processed by etching using a CF-basedgas to form the resist intermediate film pattern 4 a (FIG. 1(D)). Afterthe resist pattern 5 a is removed, by using as a mask the resistintermediate film pattern 4 a thus obtained, the resist underlayer film3 is processed by an oxygen-based plasma etching or a hydrogen-basedplasma etching to form the resist underlayer film pattern 3 a (FIG.1(E)). Further, after the resist intermediate film pattern 4 a isremoved, by using as a mask the resist underlayer film pattern 3 a, thelayer to be processed 2 is processed by etching to form the pattern 2 a(FIG. 1(F)).

When the inorganic hard mask intermediate film is used, the resistintermediate film 4 is the inorganic hard mask intermediate film; andwhen the BARC film is formed, the BARC layer is formed between theresist intermediate film 4 and the resist upper layer film 5. The BARCfilm may be etched continuously prior to etching of the resistintermediate film 4; or alternatively, after etching only the BARC film,the resist intermediate film 4 may be etched with changing the etchingequipment or the like.

As mentioned above, according to the patterning process of the presentinvention, a fine pattern can be formed by the multilayer resist method(two-layer resist process, three-layer resist process, or the four-layerresist process); and in addition, by formation of the resist underlayerfilm, steps on the substrate to be processed can be filled or thesubstrate to be processed can be planarized.

EXAMPLE

Hereunder, the present invention will be specifically explained byshowing Synthesis Examples, Examples, and Comparative Examples; however,the present invention is not restricted by these descriptions.

Meanwhile, measurement of the molecular weight was done by the methoddescribed as follows. The weight average molecular weight (Mw) and thenumber average molecular weight (Mn) were obtained on the basis ofpolystyrene equivalent by a gel permeation chromatography (GPC) using aneluent of tetrahydrofuran; and then, the dispersibility (Mw/Mn) wasobtained from these values.

Synthesis Example 1

Synthesis of Polymer (A1-1)

Propylene glycol monomethyl ether acetate (PGMEA: 23.3 g) was stirredwith heating at 80° C. under a nitrogen atmosphere. To this were addedsimultaneously and separately a mixture of 25.8 g of glycidylmethacrylate, 12.0 g of (2-phenoxyethyl)acrylic acid, 12.9 g oftricyclodecanyl acrylate, and 46.7 g of PGMEA, and a mixture of 4.45 gof dimethyl 2,2-azobis(2-methylpropionate) and 46.7 g of PGMEA during aperiod of 2 hours. After the resulting mixture was further stirred withheating for 16 hours, it was cooled to 60° C. After 200 g of heptane wasadded to it, the resulting solution was cooled to room temperature, andthen, it was allowed to stand for 2 hours. After the upper phase wasremoved by separation, 100 g of PGMEA was added to the remainingsolution; and then, heptane was removed by distillation under vacuum toobtain the PGMEA solution of the intended polymer (A1-1) as shown below.

Synthesis Examples 2 to 5

Syntheses of Polymers (A1-2) to (A1-5)

Except that monomers used as the raw materials and mole ratio thereofwere changed in accordance with the structure of each polymer, procedureof [Synthesis Example 1] was repeated to obtain the polymers (A1-2) to(A1-5) shown below,

In the following Synthesis Examples, the compounds (B1) to (B6) shownbelow were used,

Synthesis Example 6

Synthesis of Polyphenol Compound (A2-1)

Compound 1 in Table 1, compound 2 in Table 1, and 500 of2-methoxy-1-propanol were stirred with heating at 80° C. under anitrogen atmosphere. After dissolution of the compounds were confirmed,40 g of a 2-methoxy-1-propanol (PGME) solution containing 20%p-toluenesulfonic acid was slowly added to the mixture; and then, theresulting mixture was stirred at 110° C. for 12 hours. After thereaction solution was cooled to room temperature, 1,000 g of methylisobutyl ketone (MIBK) was added to the reaction solution; and then, anorganic phase was washed with 500 g of pure water for 5 times.Thereafter, the organic phase was dried by evacuation, and then, 800 mLof tetrahydrofuran (THF) was added to the dried residue, which was thenfollowed by addition of 4,000 mL of hexane for precipitation ofcrystals. The crystals thus precipitated was collected by filtration anddried under reduced pressure to obtain the polyphenol compound (A2-1).From GPC, Mw of 770 and Mw/Mn of 1.15 were obtained.

Synthesis Example 7

Synthesis of Polyphenol Compound (A2-2)

By the method based on [Synthesis Example 6], the polyphenol compound(A2-2) was obtained. From GPC, Mw of 730 and Mw/Mn of 1.12 wereobtained.

Synthesis Example 8

Synthesis of Polyphenol Compound (A2-3)

By the method based on [Synthesis Example 6], the polyphenol compound(A2-3) was obtained. From GPC, Mw of 910 and Mw/Mn of 1.04 wereobtained.

Synthesis Example 9

Synthesis of Polyphenol Compound (A2-4)

Compound 1 in Table 1, compound 2 in Table 1, and 500 of2-methoxy-1-propanol were stirred with heating at 80° C. under anitrogen atmosphere. After dissolution of the compounds were confirmed,40 g of a 2-methoxy-1-propanol (PGME) solution containing 20%p-toluenesulfonic acid was slowly added to the mixture; and then, theresulting mixture was stirred at 110° C. for 6 hours. After the reactionsolution was cooled to room temperature, 1,000 g of methyl isobutylketone (MIBK) was added to the reaction solution; and then, an organicphase was washed with 500 g of pure water for 5 times. Thereafter, theorganic phase was dried by evacuation, and then, 800 mL oftetrahydrofuran (THF) was added to the dried residue, which was thenfollowed by addition of 4,000 mL of hexane for precipitation ofcrystals. The crystals thus precipitated was collected by filtration anddried under reduced pressure to obtain the polyphenol compound (A2-4).From GPC, Mw of 1,040 and Mw/Mn of 1.03 were obtained.

TABLE 1 Synthesis Polyphenol Example Compound Compound 1 Compound 2 MwMw/Mn 6 A2-1 B1 B4 770 1.15  (40.0 g) (124.1 g) 7 A2-2 B2 B4 730 1.12 (40.0 g) (124.1 g) 8 A2-3 B3 B5 910 1.04 (115.3 g)  (33.4 g) 9 A2-4 B3B6 1,040 1.03 (115.3 g)  (47.0 g)

The polyphenol compounds used in Examples are shown below. Meanwhile,with regard to the polyphenol compound (A2-5), TEP-TPA (manufactured byAsahi Yukizai Corp.) was used,

Preparation of Resist Underlayer Film Compositions (UL-1 to UL-7 andComparative UL-1 to UL-4)

Each of the polymers (A1-1) to (A1-6), each of the polyphenol compounds(A2-1) to (A2-6), the acid generator (C1), the crosslinking agent (E1),the plasticizer (F1), and the pigment (G1) were dissolved into a solventcontaining 0.05% by mass of the surfactant PF-6320 (manufactured byOMNOVA Solutions, Inc.; this surfactant was purified by the applicant ofthe present invention) with the ratio of these substances shown in Table2; and the resulting mixture was filtrated through a 0.1-μm filter madeof a fluorinated resin to obtain each of the resist underlayer filmcompositions (UL-1 to UL-7 and Comparative UL-1 to UL-4). Meanwhile, inTable 2, PGMEA designates propylene glycol monomethyl ether acetate.

TABLE 2 Resist Polyphenol Acid Cross- underlayer Polymer compoundgenerator linking agent Plasticizer Pigment Solvent film (parts by(parts by (parts by (parts by (parts by (parts by (parts by compositionmass) mass) mass) mass) mass) mass) mass) UL-1 A1-1 A2-1 C1 — — — PGMEA(90) (10) (1) (1200) UL-2 A1-1 A2-1 C1 — — — PGMEA (70) (30) (1) (1200)UL-3 A1-2 A2-2 C1 — — — PGMEA (90) (10) (1) (1200) UL-4 A1-3 A2-3 C1 — —— PGMEA (90) (10) (1) (1200) UL-5 A1-4 A2-4 C1 — — — PGMEA (90) (10) (1)(1200) UL-6 A1-5 A2-3 C1 — — — PGMEA (90) (10) (1) (1200) UL-7 A1-4 A2-4C1 E1 F1 G1 PGMEA (90) (10) (2) (5) (2) (10) (1200) Comparative A1-1 —C1 — — — PGMEA UL-1 (100)  (1) (1200) Comparative — A2-1 — — — — PGMEAUL-2 (100)  (1200) Comparative A1-1 A2-6 C1 — — — PGMEA UL-3 (90) (10)(1) (1200) Comparative A1-6 A2-1 C1 — — — PGMEA UL-4 (90) (10) (1)(1200)

In Table 2, details of the polymer (A1-6), the polyphenol compound(A2-6), the acid generator (C1), the crosslinking agent (E1), theplasticizer (F1), and the pigment (G1) are as follows,

Measurements of Solvent Resistance and Optical Constants (Examples 1-1to 1-7 and Comparative Examples 1-1 to 1-4)

Each of the resist underlayer film compositions prepared above (UL-1 toUL-7 and Comparative UL-1 to UL-4) was applied onto the siliconsubstrate; and after it was burnt for 60 seconds at the temperatureshown in Table 3, the film thickness thereof was measured. Thereafter,PGMEA solvent was dispensed on it; and then, this was allowed to standfor 30 seconds, followed by spin drying and evaporation of the PGMEAsolvent by baking at 100° C. for 60 seconds. Then, the film thicknesswas measured again; and the solvent resistance was evaluated from thedifference in the film thickness before and after the PGMEA treatment.Further, the optical constants (refractive index “n” and extinctioncoefficient “k”) of the resist underlayer film obtained after filmformation, measured at 193 nm by a spectroscopic ellipsometer withvariable angle of incidence (VASE; manufactured by J. A. Woollam Co.,Inc.), are also shown in Table 3 below.

TABLE 3 Resist Film thickness underlayer Film thickness after solventfilm after formation: treatment: b/a × 100 Burning composition a (Å) b(Å) (%) Temp. n/k Example 1-1 UL-1 2056 2055 100 240° C. 1.66/0.35Example 1-2 UL-2 2016 2014 100 240° C. 1.61/0.42 Example 1-3 UL-3 20352032 100 240° C. 1.66/0.35 Example 1-4 UL-4 2018 2016 100 240° C.1.65/0.13 Example 1-5 UL-5 2026 2025 100 240° C. 1.64/0.10 Example 1-6UL-6 2007 2007 100 240° C. 1.65/0.35 Example 1-7 UL-7 2034 2031 100 240°C. 1.64/0.10 Comp. Example 1-1 Comp. UL-1 2024 2021 100 240° C.1.68/0.30 Comp. Example 1-2 Comp. UL-2 2024 2023 100 240° C. 1.47/0.84Comp. Example 1-3 Comp. UL-3 2038 2035 100 240° C. 1.68/0.35 Comp.Example 1-4 Comp. UL-4 2015 1108 55 240° C. 1.66/0.35

In the resist underlayer film composition of the present invention (UL-1to UL-7), it was found that all the resist underlayer film compositionsare excellent in the film-formability, hardly show a decrease in thefilm thickness by treatment with the solvent, and give the films havingan excellent solvent resistance. With regard to the optical constants,when the n-value is approximately in the range of 1.5 to 1.9 and thek-value is approximately in the range of 0.1 to 0.5, the reflected lightfrom the substrate can be significantly suppressed, so that the filmlike this can be used as the underlayer film for the photoresistpatterning, though depending on the film thickness, the upper layerfilm, and the like. In all of the above Examples the optical constantsare within the suitable ranges; and thus, it was found that they can beused for the photoresist patterning as the resist underlayer film.

Dry Etching Test in N₂/H₂-based gas system (Examples 2-1 to 2-7 andComparative Examples 2-1 to 2-5)

With regard to the resist underlayer film formed in the way as mentionedabove and the resist upper layer film formed in the way as describedbelow, the dry etching test by the N₂/H₂-based gas system was carriedout.

The resist upper layer film composition used for patterning (photoresistfor ArF) was prepared as follows: the polymer (resin) shown by the ArFmonolayer resist polymer 1, the acid generator PAG 1, and the basiccompound amine 1 were dissolved into the solvent containing 0.1% by massof FC-4430 (manufactured by Sumitomo 3M Limited) with the ratio shown inTable 4; and then, the resulting solution was filtrated through a 0.1-μmfilter made of a fluorinated resin.

TABLE 4 Acid Basic Resist upper generator compound Solvent layer filmPolymer (parts by (parts by (parts by composition (parts by mass) mass)mass) mass) PR-1 ArF monolayer PAG 1 amine 1 PGMEA resist polymer 1(100) (8.5) (0.6) (1,500)

The ArF monolayer resist polymer 1, the PAG 1, and the amine 1, whichwere used herein, are shown below,

The resist upper layer film composition obtained above (PR-1) wasapplied onto the silicon substrate and baked at 120° C. for 60 secondsto obtain the photoresist film having the thickness of about 200 nm.

The dry etching test by the N₂/H₂-based gas system was carried out underthe following condition.

Etching Condition:

Chamber pressure 2.7 Pa RF power 1,000 W N₂ gas flow rate 500 mL/minuteH₂ gas flow rate 30 mL/minute Period 20 seconds

The difference in the film thickness between before and after the dryetching was measured with the etching equipment (Telius; manufactured byTokyo Electron, Ltd.), and then, this difference was divided with theetching period to obtain the dry etching rate. The results thereof aresummarized in Table 5.

TABLE 5 Etching rate Composition (Å/s) Example 2-1 UL-1 29 Example 2-2UL-2 27 Example 2-3 UL-3 31 Example 2-4 UL-4 30 Example 2-5 UL-5 38Example 2-6 UL-6 30 Example 2-7 UL-7 38 Comp. Example 2-1 Comp. UL-1 30Comp. Example 2-2 Comp. UL-2 20 Comp. Example 2-3 Comp. UL-3 29 Comp.Example 2-4 Comp. UL-4 25 Comp. Example 2-5 PR-1 24

From the above results, in the resist underlayer film compositions ofthe present invention (UL-1 to UL-7), it was found that all the resistunderlayer films are faster in the dry etching rate as compared with theresist upper layer films (Comparative Examples 2 to 5). Therefore, theresist underlayer film composition of the present invention is suitableespecially in the manufacturing process including removal of the resistunderlayer film by the dry etching after processing of the substratebecause the residue after the removal of the resist underlayer film canbe reduced. On the other hand, in Comparative Example 2-2, it was foundthat when the resist underlayer film is removed by the dry etching, theresidue tends to be readily formed because the dry etching rate thereofis slower as compared with the resist upper layer film.

Evaluation of the Gap-Filling Characteristic (Examples 3-1 to 3-7 andComparative Examples 3-1 to 3-4)

Each of the resist underlayer film compositions mentioned above wasapplied onto the SiO₂ wafer substrate having a dense hole pattern (holediameter: 0.16 μm, hole depth: 0.50 μm, and distance between the centersof neighboring two holes: 0.32 μm), and then, it was burnet at thetemperature described in Table 6 for the period of 60 seconds to formthe resist underlayer film. The substrate used is the underlaymentsubstrate 7 (SiO₂ wafer substrate) having the dense hole pattern asdepicted in FIG. 2(G) (bird's eye view) and FIG. 2(H) (cross sectionview). The shape of the cross section of each wafer substrate wasobserved with a scanning electron microscope (SEM) so as to confirmwhether or not inside the hole is filled with the resist underlayer filmwithout any void. The results thereof are summarized in Table 6. Whenthe resist underlayer film composition that is poor in the gap-fillingcharacteristic is used, the voids are formed inside the holes in thisevaluation. When the resist underlayer film composition that isexcellent in the gap-filling characteristic is used, the resistunderlayer film 8 is filled inside the holes without forming the voidsas illustrated in FIG. 2(I) in this evaluation.

TABLE 6 Resist underlayer film composition Burning temp. Void Example3-1 UL-1 240° C. Not formed Example 3-2 UL-2 240° C. Not formed Example3-3 UL-3 240° C. Not formed Example 3-4 UL-4 240° C. Not formed Example3-5 UL-5 240° C. Not formed Example 3-6 UL-6 240° C. Not formed Example3-7 UL-7 240° C. Not formed Comp. Example 3-1 Comp. UL-1 240° C. Notformed Comp. Example 3-2 Comp. UL-2 240° C. Not formed Comp. Example 3-3Comp. UL-3 240° C. Not formed Comp. Example 3-4 Comp. UL-4 240° C. Notformed

From the above results, it was found that the resist underlayer filmcompositions of Examples (UL-1 to UL-7) can fill the hole patternwithout forming the voids.

Evaluation of the Planarization Characteristic (Examples 4-1 to 4-7 andComparative Examples 4-1 to 4-4)

Each of the resist underlayer film compositions described above wasapplied onto the underlayment substrate 9 (SiO₂ wafer substrate) havinga giant isolated trench pattern (FIG. 3(J), trench width: 10 μm, andtrench depth: 0.1 μm) and then, it was burnt under the conditiondescribed in Table 7. Then, the difference in the film thickness betweenthe trench portion and the non-trench portion of the resist underlayerfilm 10 (delta 10 in FIG. 3(K)) was observed with an atomic forcemicroscope (AFM). The results are summarized in Table 7. In thisevaluation, it can be said that as the difference in the film thicknessis smaller, the planarization characteristic is better.

TABLE 7 Resist underlayer Difference in film film thickness compositionBurning condition (nm) Example 4-1 UL-1 240° C. × 60 sec. 55 Example 4-2UL-2 240° C. × 60 sec. 45 Example 4-3 UL-3 240° C. × 60 sec. 55 Example4-4 UL-4 240° C. × 60 sec. 50 Example 4-5 UL-5 240° C. × 60 sec. 55Example 4-6 UL-6 240° C. × 60 sec. 50 Example 4-7 UL-7 240° C. × 60 sec.55 Comp. Example 4-1 Comp. UL-1 240° C. × 60 sec. 60 Comp. Example 4-2Comp. UL-2 240° C. × 60 sec. 40 Comp. Example 4-3 Comp. UL-3 240° C. ×60 sec. 60 Comp. Example 4-4 Comp. UL-4 240° C. × 60 sec. 65

From the above results, it was found that the resist underlayer filmcompositions of the present invention (UL-1 to UL-7) have smallerdifference between the trench portion and the non-trench portion in thethickness of the resist underlayer film as compared with the resistunderlayer film compositions of the Comparative Examples (ComparativeUL-1, UL-3, and UL-4), and thus, they are excellent in the planarizationcharacteristic.

Evaluation of Resistance to the Basic Hydrogen Peroxide Aqueous Solution(Examples 6-1 to 6-7 and Comparative Examples 6-1 to 6-4)

The resist underlayer film composition was applied onto the siliconwafer cut to the size of 3-cm square, and then, it was burnt with thecondition described in Table 8 so as to form the film with the thicknessof about 100 nm. This wafer piece was soaked in the 1.0% by masshydrogen peroxide aqueous solution containing 0.5% by mass of ammonia at70° C. for 5 minutes. And then, after this was rinsed with deionizedwater, whether or not the resist underlayer film was delaminated fromthe wafer was visually checked. When, part or all of the resistunderlayer film is delaminated thereby resulting in exposure of thesilicon wafer surface, it is judged that the resist underlayer filmtested has insufficient resistance to the basic hydrogen peroxideaqueous solution. These results are summarized in Table 8.

TABLE 8 Resist underlayer film Burning Test result composition condition(70° C. × 5 min.) Example 6-1 UL-1 240° C. × 60 sec. No delaminationExample 6-2 UL-2 240° C. × 60 sec. No delamination Example 6-3 UL-3 240°C. × 60 sec. No delamination Example 6-4 UL-4 240° C. × 60 sec. Nodelamination Example 6-5 UL-5 240° C. × 60 sec. No delamination Example6-6 UL-6 240° C. × 60 sec. No delamination Example 6-7 UL-7 240° C. × 60sec. No delamination Comp. Example 6-1 Comp. UL-1 240° C. × 60 sec.Total delamination Comp. Example 6-2 Comp. UL-2 240° C. × 60 sec. Totaldelamination Comp. Example 6-3 Comp. UL-3 240° C. × 60 sec. Totaldelamination Comp. Example 6-4 Comp. UL-4 240° C. × 60 sec. Totaldelamination

From the above results, it was found that the resist underlayer filmcompositions of Examples (UL-1 to UL-7) are superior to the resistunderlayer film compositions of Comparative Examples (ComparativeExamples UL-1 to UL-4) in the resistance to the basic hydrogen peroxideaqueous solution.

Evaluation of Patterning (Examples 7-1 to 7-7 and Comparative Examples7-1 to 7-4)

Each of the resist underlayer film compositions described above (UL-1 toUL-7 and Comparative UL-1 to UL-4) was applied onto the Si wafersubstrate, and then, it was burnt with the condition described in Table9 to form the resist underlayer film. The resist upper layer filmcomposition mentioned before (PR-1) was applied onto the resistunderlayer film thus formed, and then, it was baked at 120° C. for 60seconds to form the photoresist film having the film thickness of about200 nm.

Next, the photoresist film thus formed was exposed to a light by usingthe ArF immersion exposure instrument (NSR-S610C; manufactured by NikonCorp, NA: 0.85, σ: 0.75, conventional illumination, 6% half tone phaseshift mask). Then, after the photoresist film thus exposed was baked at100° C. for 60 seconds (PEB), it was developed for 30 seconds by usingan aqueous 2.38% by mass of tetramethyl ammonium hydroxide (TMAH)solution to obtain the 160 nm 1:1 positive lines-and-spaces (L/S)photoresist pattern.

Next, the resist underlayer film was etched by dry etching using theetching equipment (Telius; manufactured by Tokyo Electron, Ltd.) byusing the photoresist pattern as a mask to form the resist underlayerfilm pattern. The etching condition is described below.

Transcription condition of the photoresist pattern to the resistunderlayer film:

Chamber pressure 2.7 Pa RF power 1,000 W N₂ gas flow rate 500 mL/minuteH₂ gas flow rate 30 mL/minute Period 40 seconds

Formation of the resist underlayer film pattern was confirmed by thetop-down SEM view of the wafer after etching of the underlayer film.Next, the wafer was cut to the width of 2 cm; and this wafer piece wassoaked in the aqueous 1.0% by mass hydrogen peroxide aqueous solutioncontaining 0.5% by mass of ammonia for 5 minutes at 70° C., rinsed withdeionized water and dried, and then observed by using an opticalmicroscope so as to evaluate whether or not the delamination of theresist underlayer film pattern took place. The evaluation results aresummarized in Table 9.

TABLE 9 Resist underlayer Resist film underlayer composition Burningcondition film pattern Delamination Example 7-1 UL-1 240° C. × 60 sec.Formable No delamination Example 7-2 UL-2 240° C. × 60 sec. Formable Nodelamination Example 7-3 UL-3 240° C. × 60 sec. Formable No delaminationExample 7-4 UL-4 240° C. × 60 sec. Formable No delamination Example 7-5UL-5 240° C. × 60 sec. Formable No delamination Example 7-6 UL-6 240° C.× 60 sec. Formable No delamination Example 7-7 UL-7 240° C. × 60 sec.Formable No delamination Comp. Example Comp. UL-1 240° C. × 60 sec.Formable Delaminated 7-1 Comp. Example Comp. UL-2 240° C. × 60 sec.Formable Delaminated 7-2 Comp. Example Comp. UL-3 240° C. × 60 sec.Formable Delaminated 7-3 Comp. Example Comp. UL-4 240° C. × 60 sec. Notformable — 7-4

From the above results, it was found that in all the resist underlayerfilm compositions of the present invention (Examples 7-1 to 7-7), theupper layer resist pattern is satisfactorily transcribed to the resistunderlayer film so that the resist underlayer film composition of thepresent invention can be suitably used in the fine lithography by themultilayer resist method. In addition, it could be confirmed that theformed resist underlayer film pattern is excellent in the resistance tothe basic hydrogen peroxide aqueous solution. Therefore, the resistunderlayer film composition and patterning process of the presentinvention are useful especially because they enable to manufacture asemiconductor device by fine processing in which the multilayer resistmethod and the chemical etching method using a chemical such as thebasic hydrogen peroxide aqueous solution are combined. On the otherhand, in Comparative Examples 7-1, 7-2, and 7-3, although the resistunderlayer film pattern can be formed, the resistance of the formedresist underlayer film pattern to the basic hydrogen peroxide aqueoussolution is not so high to prevent delamination from occurring. InComparative Example 7-4, the resist underlayer film pattern could not beformed.

From the above, it became apparent that the resist underlayer filmcomposition, the patterning process, and the method for forming theresist underlayer film of the present invention can be suitably used inthe multilayer resist process for the fine patterning in thesemiconductor device manufacturing, and especially these can also beused in the multilayer resist process including the wet etching process,so that these are extremely useful in industry.

It must be noted here that the present invention is not limited to theembodiments as described above. The foregoing embodiments are mereexamples; any form having substantially the same composition as thetechnical idea described in claims of the present invention and showingsimilar effects is included in the technical scope of the presentinvention.

EXPLANATIONS OF LETTERS OR NUMERALS

-   1: Substrate, 2: layer to be processed,-   2a: pattern formed on the substrate,-   3: resist underlayer film,-   3 a: resist underlayer film pattern,-   4: resist intermediate film,-   4 a: resist intermediate film pattern,-   5: resist upper layer film, 5 a: resist pattern,-   6: prescribed portion,-   7: underlayment substrate having dense hole pattern,-   8: resist underlayer film,-   9: underlayment substrate having giant isolated trench pattern,-   10: resist underlayer film,-   delta 10: difference in film thickness of the resist underlayer film    between the trench portion and the non-trench portion.

What is claimed is:
 1. A resist underlayer film composition, wherein theresist underlayer film composition is used for a multilayer resistmethod, comprising: (A1) a polymer (1A) comprising one, or two or more,of a repeating unit represented by following general formula (1), (A2)one, or two or more, of a polyphenol compound having a formula weight of2,000 or less and not having a 3,4-dihydroxy phenyl group; and (B) anorganic solvent,

wherein R⁰¹ represents a hydrogen atom or a methyl group; and R⁰²represents a group selected from following formulae (1-1) to (1-3),

wherein the dotted line represents a bonding hand.
 2. The resistunderlayer film composition according to claim 1, wherein the (A2)component contains any one of a compound represented by followinggeneral formula (2A) and a compound represented by following generalformula (3A) or both,R

X′)_(m2)   (2A) wherein R represents a single bond or an organic grouphaving 1 to 50 carbon atoms; X′ represents a group represented byfollowing general formula (2B); and “m2” represents an integersatisfying 1≤m2≤5,

wherein “n3” represents 0 or 1; “n4” represents 1 or 2; X⁴ represents agroup represented by following general formula (2C); and “n6” represents0, 1, or 2; however, “n4” represents 1 when “n3” is 0 and “n6” is 0,

wherein R¹¹ represents a hydrogen atom or a saturated or unsaturatedhydrocarbon group having 1 to 10 carbon atoms, and the hydrogen atom onthe benzene ring may be optionally substituted by a methyl group or amethoxy group,

wherein R¹⁰¹, R¹⁰², R¹⁰³, and R¹⁰⁴ each represents independently ahydrogen atom or a hydroxyl group; “m100” represent 1, 2, or 3; R¹⁰⁰represents a hydrogen atom or a hydroxyl group when “m100” is 1, or asingle bond or a group represented by following general formula (3B)when “m100” is 2, or a group represented by following general formula(3C) when “m100” is 3, and the hydrogen atom on the benzene ring may beoptionally substituted by a methyl group, a methoxy group, ahydroxymethyl group, or a methoxymethyl group; “m101” represents 0 or 1,“m102” represents 1 or 2, “m103” represents 0 or 1, “m104” represents 1or 2, and “m105” represents 0 or 1; when “m101” is 0, “n101” and “n102”represent an integer satisfying 0≤n101≤3, 0≤n102≤3, and 1≤n101+n102≤4;when “m101” is 1, “n101”, “n102”, “n103”, and “n104” represent aninteger satisfying 0≤n101≤2, 0≤n102≤2, 0≤n103≤2, 0≤n104≤2, and2≤n101+n102+n103+n104≤8; however, when “m101” is 0 and “n102” is 0,“n101” represents 0 or 1 and “m100” represents 2 or 3; when “m103” is 0,“m102” represents 1; and when “m105” is 0, “m104” represents 1,

wherein * represents a bonding site; R¹⁰⁶ and R¹⁰⁷ represent a hydrogenatom or an organic group having 1 to 24 carbon atoms; and R⁻¹⁰⁶ and R¹⁰⁷may be bonded to form a ring structure,

wherein * represents a bonding site; and R¹⁰⁸ represents a hydrogen atomor an organic group having 1 to 15 carbon atoms.
 3. The resistunderlayer film composition according to claim 1, wherein the polymer(1A) further contains one, or two or more, of a repeating unitrepresented by following general formula (2),

wherein R⁰¹ represents the same as before; A¹ represents a single bond,—CO₂—, or a divalent connecting group having 2 to 10 carbon atoms andincluding —CO₂—; and Ar¹ represents a substituted or unsubstituted arylgroup having 6 to 20 carbon atoms.
 4. The resist underlayer filmcomposition according to claim 1, wherein the polymer (1A) furthercontains one, or two or more, of a repeating unit represented byfollowing general formula (3),

wherein R⁰¹ represents the same as before; and R^(c) represents amonovalent group having 3 to 20 carbon atoms and having an alicyclicstructure.
 5. The resist underlayer film composition according to claim1, wherein a weight average molecular weight of the polymer (1A) is in arange of 1,000 to 20,000.
 6. The resist underlayer film compositionaccording to claim 1, wherein the resist underlayer film compositionfurther contains one or more additives out of (C) an acid generator, (D)a surfactant, (E) a crosslinking agent, (F) a plasticizer, and (G) apigment.
 7. The resist underlayer film composition according to claim 1,wherein the resist underlayer film composition is the resist underlayerfilm composition which gives a resist underlayer film having aresistance to an ammonia-containing hydrogen peroxide aqueous solution.8. The resist underlayer film composition according to claim 7, whereinthe resist underlayer film is the resist underlayer film which does notshow any peel-off when a silicon substrate formed with the resistunderlayer film is soaked into a 1.0% by mass hydrogen peroxide aqueoussolution containing 0.5% by mass of ammonia at 70° C. for 5 minutes. 9.A patterning process, wherein the patterning process is to form apattern on a substrate to be processed and comprises: (I-1) forming aresist underlayer film on the substrate to be processed by using theresist underlayer film composition according to claim 1, (I-2) forming aresist upper layer film on the resist underlayer film by using aphotoresist composition, (I-3) forming a pattern on the resist upperlayer film by developing the resist upper layer film by using adeveloper after the resist upper layer film is pattern-exposed, and(I-4) transcribing the pattern to the resist underlayer film by dryetching using as a mask the resist upper layer film formed with thepattern.
 10. A patterning process, wherein the patterning process is toform a pattern on a substrate to be processed and comprises: (II-1)forming a resist underlayer film on the substrate to be processed byusing the resist underlayer film composition according to claim 1,(II-2) forming a resist intermediate film on the resist underlayer film,(II-3) forming a resist upper layer film on the resist intermediate filmby using a photoresist composition, (II-4) forming a pattern on theresist upper layer film by developing the resist upper layer film byusing a developer after the resist upper layer film is pattern-exposed,(II-5) transcribing the pattern to the resist intermediate film by dryetching using as a mask the resist upper layer film formed with thepattern, and (II-6) transcribing the pattern to the resist underlayerfilm by dry etching using as a mask the resist intermediate filmtranscribed with the pattern.
 11. A patterning process, wherein thepatterning process is to form a pattern on a substrate to be processedand comprises: (III-1) forming a resist underlayer film on the substrateto be processed by using the resist underlayer film compositionaccording to claim 1, (III-2) forming an inorganic hard maskintermediate film selected from a silicon oxide film, a silicon nitridefilm, and a silicon oxide nitride film on the resist underlayer film,(III-3) forming an organic antireflective film on the inorganic hardmask intermediate film, (III-4) forming a resist upper layer film on theorganic antireflective film by using a photoresist composition, (III-5)forming a pattern on the resist upper layer film by developing theresist upper layer film by using a developer after the resist upperlayer film is pattern-exposed, (III-6) transcribing the pattern to theorganic antireflective film and the inorganic hard mask intermediatefilm by dry etching using as a mask the resist upper layer film formedwith the pattern, and (III-7) transcribing the pattern to the resistunderlayer film by dry etching using as a mask the inorganic hard maskintermediate film transcribed with the pattern.
 12. The patterningprocess according to claim 10, wherein after the (II-6) step, thepatterning process further has a step in which the resist intermediatefilm transcribed with the pattern is removed by wet etching using abasic hydrogen peroxide aqueous solution.
 13. The patterning processaccording to claim 9, wherein after the (I-4) step, the (II-6) step, orthe (III-7) step, the patterning process further has a step in which thepattern is transcribed to the substrate to be processed by wet etchingusing a basic hydrogen peroxide aqueous solution and the resistunderlayer film transcribed with the pattern as a mask.
 14. Thepatterning process according to claim 9, wherein after the (I-4) step,the (II-6) step, or the (III-7) step, the patterning process further hasa step in which the substrate to be processed is pattern-processed by anion implantation using as a mask the resist underlayer film transcribedwith the pattern.
 15. The patterning process according to claim 14,wherein after the step of the patterning process of the substrate to beprocessed by the ion implantation, the patterning process further has astep in which the resist intermediate film transcribed with the patternis removed by wet etching using a basic hydrogen peroxide aqueoussolution.
 16. The patterning process according to claim 9, wherein theresist underlayer film composition having a dry etching rate faster thana dry etching rate of the resist upper layer film is used.
 17. Thepatterning process according to claim 9, wherein the resist underlayerfilm is formed by applying the resist underlayer film composition ontothe substrate to be processed followed by heat-treatment thereof in atemperature 100° C. or more and 300° C. or less, both ends inclusive,for a period of 10 seconds or more and 600 seconds or less.
 18. Thepatterning process according to claim 9, wherein as the substrate to beprocessed, a substrate having a structural body with a height of 30 nmor more, or having a step is used.
 19. A method for forming a resistunderlayer film, wherein the resist underlayer film compositionaccording to claim 1 is applied onto a substrate to be processed, andthen, the resist underlayer film composition is subjected toheat-treatment in a temperature 100° C. or more and 300° C. or less,both ends inclusive, for a period of 10 seconds or more and 600 secondsor less to form a cured film.
 20. The method for forming the resistunderlayer film according to claim 19, wherein as the substrate to beprocessed, a substrate having a structural body with a height of 30 nmor more, or having a step is used.